We Keep Coding

How to optimize recursive function for a graph for clearing and settlement

I have to make a module in an Insurance application that deals with clearing and settlement (I think this is the correct financial terminology) between insurance companies enroled in the system. Practically, the system must pair all the amounts that companies have to pay to one another, and only the unpaired (remaining) sums to be paid through the bank. For now there are about 30 companies in the system.
All the readings I did about clearing and settlement pointed me towards graphs and graphs theory (which I have studied in the highschool quite a long time ago).
For a system with 4 companies the graph would look like this:
where each company represents a node (N1 ... N4) and each weighted edge represents the amount that a company has to pay to the other. In my code, the nodes are int, representing the id's of the companies.
What I did so far... I created the graph (for test I used the Random generator for the amounts) and made a recursive function to calculate all posible cycles in the graph. Then I made another recursive function that takes all non-zero cycles starting with the longest path with maximum common sum to pair.
The algorithm seems valid in terms of final results, but for graphs bigger than 7-8 nodes it takes too long to complete. The problem is in the recursive function that creates the possible cycles in the graph. Here is my code:
static void Main(string[] args)
{
int nodes = 4;
try
{
nodes = Convert.ToInt32(args[0]);
}
catch { }
DateTime start = DateTime.Now;
Graph g = new Graph(nodes);
int step = 0;
double CompensatedAmount = 0;
double TotalCompensatedAmount = 0;
DateTime endGeneration = DateTime.Now;
Console.WriteLine("Graph generated in: " + (endGeneration - start).TotalSeconds + " seconds.");
Compensare.RunCompensation(false, g, step, CompensatedAmount, TotalCompensatedAmount, out CompensatedAmount, out TotalCompensatedAmount);
DateTime endCompensation = DateTime.Now;
Console.WriteLine("Graph compensated in: " + (endCompensation - endGeneration).TotalSeconds + " seconds.");
}
... and the main class:
public static class Compensare
{
public static void RunCompensation(bool exit, Graph g, int step, double prevCompensatedAmount, double prevTotalCompensatedAmount, out double CompensatedAmount, out double TotalCompensatedAmount)
{
step++;
CompensatedAmount = prevCompensatedAmount;
TotalCompensatedAmount = prevTotalCompensatedAmount;
if (!exit)
{
List<Cycle> orderedList = g.Cycles.OrderByDescending(x => x.CycleCompensatedAmount).ToList();
g.ListCycles(orderedList, "OrderedCycles" + step.ToString() + ".txt");
using (Graph clona = g.Clone())
{
int maxCycleIndex = clona.GetMaxCycleByCompensatedAmount();
double tmpCompensatedAmount = clona.Cycles[maxCycleIndex].CycleMin;
exit = tmpCompensatedAmount <= 0 ? true : false;
CompensatedAmount += tmpCompensatedAmount;
TotalCompensatedAmount += (tmpCompensatedAmount * clona.Cycles[maxCycleIndex].EdgesCount);
clona.CompensateCycle(maxCycleIndex);
clona.UpdateCycles();
Console.WriteLine(String.Format("{0} - edges: {4} - min: {3} - {1} - {2}\r\n", step, CompensatedAmount, TotalCompensatedAmount, tmpCompensatedAmount, clona.Cycles[maxCycleIndex].EdgesCount));
RunCompensation(exit, clona, step, CompensatedAmount, TotalCompensatedAmount, out CompensatedAmount, out TotalCompensatedAmount);
}
}
}
}
public class Edge
{
public int Start { get; set; }
public int End { get; set; }
public double Weight { get; set; }
public double InitialWeight {get;set;}
public Edge() { }
public Edge(int _start, int _end, double _weight)
{
this.Start = _start;
this.End = _end;
this.Weight = _weight;
this.InitialWeight = _weight;
}
}
public class Cycle
{
public List<Edge> Edges = new List<Edge>();
public double CycleWeight = 0;
public double CycleMin = 0;
public double CycleMax = 0;
public double CycleAverage = 0;
public double CycleCompensatedAmount = 0;
public int EdgesCount = 0;
public Cycle() { }
public Cycle(List<Edge> _edges)
{
this.Edges = new List<Edge>(_edges);
UpdateCycle();
}
public void UpdateCycle()
{
UpdateCycle(this);
}
public void UpdateCycle(Cycle c)
{
double sum = 0;
double min = c.Edges[0].Weight;
double max = c.Edges[0].Weight;
for(int i=0;i<c.Edges.Count;i++)
{
sum += c.Edges[i].Weight;
min = c.Edges[i].Weight < min ? c.Edges[i].Weight : min;
max = c.Edges[i].Weight > max ? c.Edges[i].Weight : max;
}
c.EdgesCount = c.Edges.Count;
c.CycleWeight = sum;
c.CycleMin = min;
c.CycleMax = max;
c.CycleAverage = sum / c.EdgesCount;
c.CycleCompensatedAmount = min * c.EdgesCount;
}
}
public class Graph : IDisposable
{
public List<int> Nodes = new List<int>();
public List<Edge> Edges = new List<Edge>();
public List<Cycle> Cycles = new List<Cycle>();
public int NodesCount { get; set; }
public Graph() { }
public Graph(int _nodes)
{
this.NodesCount = _nodes;
GenerateNodes();
GenerateEdges();
GenerateCycles();
}
private int FindNode(string _node)
{
for(int i = 0; i < this.Nodes.Count; i++)
{
if (this.Nodes[i].ToString() == _node)
return i;
}
return 0;
}
private int FindEdge(string[] _edge)
{
for(int i = 0; i < this.Edges.Count; i++)
{
if (this.Edges[i].Start.ToString() == _edge[0] && this.Edges[i].End.ToString() == _edge[1] && Convert.ToDouble(this.Edges[i].Weight) == Convert.ToDouble(_edge[2]))
return i;
}
return 0;
}
public Graph Clone()
{
Graph clona = new Graph();
clona.Nodes = new List<int>(this.Nodes);
clona.Edges = new List<Edge>(this.Edges);
clona.Cycles = new List<Cycle>(this.Cycles);
clona.NodesCount = this.NodesCount;
return clona;
}
public void CompensateCycle(int cycleIndex)
{
for(int i = 0; i < this.Cycles[cycleIndex].Edges.Count; i++)
{
this.Cycles[cycleIndex].Edges[i].Weight -= this.Cycles[cycleIndex].CycleMin;
}
}
public int GetMaxCycleByCompensatedAmount()
{
int toReturn = 0;
for (int i = 0; i < this.Cycles.Count; i++)
{
if (this.Cycles[i].CycleCompensatedAmount > this.Cycles[toReturn].CycleCompensatedAmount)
{
toReturn = i;
}
}
return toReturn;
}
public void GenerateNodes()
{
for (int i = 0; i < this.NodesCount; i++)
{
this.Nodes.Add(i + 1);
}
}
public void GenerateEdges()
{
Random r = new Random();
for(int i = 0; i < this.Nodes.Count; i++)
{
for(int j = 0; j < this.Nodes.Count; j++)
{
if(this.Nodes[i] != this.Nodes[j])
{
int _weight = r.Next(0, 500);
Edge e = new Edge(this.Nodes[i], this.Nodes[j], _weight);
this.Edges.Add(e);
}
}
}
}
public void GenerateCycles()
{
for(int i = 0; i < this.Edges.Count; i++)
{
FindCycles(new Cycle(new List<Edge>() { this.Edges[i] }));
}
this.UpdateCycles();
}
public void UpdateCycles()
{
for (int i = 0; i < this.Cycles.Count; i++)
{
this.Cycles[i].UpdateCycle();
}
}
private void FindCycles(Cycle path)
{
List<Edge> nextPossibleEdges = GetNextEdges(path.Edges[path.Edges.Count - 1].End);
for (int i = 0; i < nextPossibleEdges.Count; i++)
{
if (path.Edges.IndexOf(nextPossibleEdges[i]) < 0) // the edge shouldn't be already in the path
{
Cycle temporaryPath = new Cycle(path.Edges);
temporaryPath.Edges.Add(nextPossibleEdges[i]);
if (nextPossibleEdges[i].End == temporaryPath.Edges[0].Start) // end of path - valid cycle
{
if (!CycleExists(temporaryPath))
{
this.Cycles.Add(temporaryPath);
break;
}
}
else
{
FindCycles(temporaryPath);
}
}
}
}
private bool CycleExists(Cycle cycle)
{
bool toReturn = false;
if (this.Cycles.IndexOf(cycle) > -1) { toReturn = true; }
else
{
for (int i = 0; i < this.Cycles.Count; i++)
{
if (this.Cycles[i].Edges.Count == cycle.Edges.Count && !CompareEdges(this.Cycles[i].Edges[0], cycle.Edges[0]))
{
bool cycleExists = true;
for (int j = 0; j < cycle.Edges.Count; j++)
{
bool edgeExists = false; // if there is an edge not in the path, then the searched cycle is diferent from the current cycle and we can pas to the next iteration
for (int k = 0; k < this.Cycles[i].Edges.Count; k++)
{
if (CompareEdges(cycle.Edges[j], this.Cycles[i].Edges[k]))
{
edgeExists = true;
break;
}
}
if (!edgeExists)
{
cycleExists = false;
break;
}
}
if (cycleExists) // if we found an cycle with all edges equal to the searched cycle, then the cycle is not valid
{
toReturn = true;
break;
}
}
}
}
return toReturn;
}
private bool CompareEdges(Edge e1, Edge e2)
{
return (e1.Start == e2.Start && e1.End == e2.End && e1.Weight == e2.Weight);
}
private List<Edge> GetNextEdges(int endNode)
{
List<Edge> tmp = new List<Edge>();
for(int i = 0; i < this.Edges.Count; i++)
{
if(endNode == this.Edges[i].Start)
{
tmp.Add(this.Edges[i]);
}
}
return tmp;
}
#region IDisposable Support
private bool disposedValue = false; // To detect redundant calls
protected virtual void Dispose(bool disposing)
{
if (!disposedValue)
{
if (disposing)
{
// TODO: dispose managed state (managed objects).
this.Nodes = null;
this.Edges = null;
this.Cycles = null;
this.NodesCount = 0;
}
// TODO: free unmanaged resources (unmanaged objects) and override a finalizer below.
// TODO: set large fields to null.
disposedValue = true;
}
}
// TODO: override a finalizer only if Dispose(bool disposing) above has code to free unmanaged resources.
// ~Graph() {
// // Do not change this code. Put cleanup code in Dispose(bool disposing) above.
// Dispose(false);
// }
// This code added to correctly implement the disposable pattern.
public void Dispose()
{
// Do not change this code. Put cleanup code in Dispose(bool disposing) above.
Dispose(true);
// TODO: uncomment the following line if the finalizer is overridden above.
// GC.SuppressFinalize(this);
}
#endregion
}
I've found several articles/answers about graphs, both in Java and C# (including quickgraph), but they mainly focus on directed graphs (without cycles).
I have also read about tail call optimization, for recursion, but I don't know if/how to implement in my case.
I now there is a lot to grasp about this subject, but maybe someone had to deal with something similar and can either help me optimize the code (which as I said seems to do the job in the end), either point me to another direction to rethink the whole process.

I think you can massively simplify this.
All money is the same, so (using your example) N1 doesn't care whether it gets 350 from N2 and pays 150 to N2 and so on - N1 merely cares that overall it ends up 145 down (if I've done the arithmetic correctly). Similarly, each other N only cares about its overall position. So, summing the inflows and outflows at each node, we get:
Company Net position
N1 -145
N2 -65
N3 +195
N4 +15
So with someone to act as a central clearing house - the bank - simply arrange for N1 and N2 to pay the clearing house 145 and 65 respectively, and for N3 and N4 to receive 195 and 15 respectively from the clearing house. And everyone's happy.
I may have missed some aspect, of course, in which case I'm sure someone will point it out...

Importing and removing duplicates from a massive amount of text files using C# and Redis

This is a bit of a doozy and it's been a while since I worked with C#, so bear with me:
I'm running a jruby script to iterate through 900 files (5 Mb - 1500 Mb in size) to figure out how many dupes STILL exist within these (already uniq'd) files. I had little luck with awk.
My latest idea was to insert them into a local MongoDB instance like so:
db.collection('hashes').update({ :_id => hash}, { $inc: { count: 1} }, { upsert: true)
... so that later I could just query it like db.collection.where({ count: { $gt: 1 } }) to get all the dupes.
This is working great except it's been over 24 hours and at the time of writing I'm at 72,532,927 Mongo entries and growing.
I think Ruby's .each_line is bottlnecking the IO hardcore:
So what I'm thinking now is compiling a C# program which fires up a thread PER EACH FILE and inserts the line (md5 hash) into a Redis list.
From there, I could have another compiled C# program simply pop the values off and ignore the save if the count is 1.
So the questions are:
Will using a compiled file reader and multithreading the file reads significantly improve performance?
Is using Redis even necessary? With a tremendous amount of AWS memory, could I not just use the threads to fill some sort of a list atomically and proceed from there?
Thanks in advance.

Updated
New solution. Old solution. The main idea is to calculate dummy hashes(just sum of all chars in string) of each line and store it in Dictionary<ulong, List<LinePosition>> _hash2LinePositions. It's possible to have multiple hashes in the same stream and it solves by List in Dictionary Value. When the hashes are the same, we read and compare the strings from the streams. LinePosition is using for storing info about line - position in stream and its length. I don't have such huge files as you, but my tests shows that it works. Here is the full code:
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
public class Solution
{
struct LinePosition
{
public long Start;
public long Length;
public LinePosition(long start, long count)
{
Start = start;
Length = count;
}
public override string ToString()
{
return string.Format("Start: {0}, Length: {1}", Start, Length);
}
}
class TextFileHasher : IDisposable
{
readonly Dictionary<ulong, List<LinePosition>> _hash2LinePositions;
readonly Stream _stream;
bool _isDisposed;
public HashSet<ulong> Hashes { get; private set; }
public string Name { get; private set; }
public TextFileHasher(string name, Stream stream)
{
Name = name;
_stream = stream;
_hash2LinePositions = new Dictionary<ulong, List<LinePosition>>();
Hashes = new HashSet<ulong>();
}
public override string ToString()
{
return Name;
}
public void CalculateFileHash()
{
int readByte = -1;
ulong dummyLineHash = 0;
// Line start position in file
long startPosition = 0;
while ((readByte = _stream.ReadByte()) != -1) {
// Read until new line
if (readByte == '\r' || readByte == '\n') {
// If there was data
if (dummyLineHash != 0) {
// Add line hash and line position to the dict
AddToDictAndHash(dummyLineHash, startPosition, _stream.Position - 1 - startPosition);
// Reset line hash
dummyLineHash = 0;
}
}
else {
// Was it new line ?
if (dummyLineHash == 0)
startPosition = _stream.Position - 1;
// Calculate dummy hash
dummyLineHash += (uint)readByte;
}
}
if (dummyLineHash != 0) {
// Add line hash and line position to the dict
AddToDictAndHash(dummyLineHash, startPosition, _stream.Position - startPosition);
// Reset line hash
dummyLineHash = 0;
}
}
public List<LinePosition> GetLinePositions(ulong hash)
{
return _hash2LinePositions[hash];
}
public List<string> GetDuplicates()
{
List<string> duplicates = new List<string>();
foreach (var key in _hash2LinePositions.Keys) {
List<LinePosition> linesPos = _hash2LinePositions[key];
if (linesPos.Count > 1) {
duplicates.AddRange(FindExactDuplicates(linesPos));
}
}
return duplicates;
}
public void Dispose()
{
if (_isDisposed)
return;
_stream.Dispose();
_isDisposed = true;
}
private void AddToDictAndHash(ulong hash, long start, long count)
{
List<LinePosition> linesPosition;
if (!_hash2LinePositions.TryGetValue(hash, out linesPosition)) {
linesPosition = new List<LinePosition>() { new LinePosition(start, count) };
_hash2LinePositions.Add(hash, linesPosition);
}
else {
linesPosition.Add(new LinePosition(start, count));
}
Hashes.Add(hash);
}
public byte[] GetLineAsByteArray(LinePosition prevPos)
{
long len = prevPos.Length;
byte[] lineBytes = new byte[len];
_stream.Seek(prevPos.Start, SeekOrigin.Begin);
_stream.Read(lineBytes, 0, (int)len);
return lineBytes;
}
private List<string> FindExactDuplicates(List<LinePosition> linesPos)
{
List<string> duplicates = new List<string>();
linesPos.Sort((x, y) => x.Length.CompareTo(y.Length));
LinePosition prevPos = linesPos[0];
for (int i = 1; i < linesPos.Count; i++) {
if (prevPos.Length == linesPos[i].Length) {
var prevLineArray = GetLineAsByteArray(prevPos);
var thisLineArray = GetLineAsByteArray(linesPos[i]);
if (prevLineArray.SequenceEqual(thisLineArray)) {
var line = System.Text.Encoding.Default.GetString(prevLineArray);
duplicates.Add(line);
}
#if false
string prevLine = System.Text.Encoding.Default.GetString(prevLineArray);
string thisLine = System.Text.Encoding.Default.GetString(thisLineArray);
Console.WriteLine("PrevLine: {0}\r\nThisLine: {1}", prevLine, thisLine);
StringBuilder sb = new StringBuilder();
sb.Append(prevPos);
sb.Append(" is '");
sb.Append(prevLine);
sb.Append("'. ");
sb.AppendLine();
sb.Append(linesPos[i]);
sb.Append(" is '");
sb.Append(thisLine);
sb.AppendLine("'. ");
sb.Append("Equals => ");
sb.Append(prevLine.CompareTo(thisLine) == 0);
Console.WriteLine(sb.ToString());
#endif
}
else {
prevPos = linesPos[i];
}
}
return duplicates;
}
}
public static void Main(String[] args)
{
List<TextFileHasher> textFileHashers = new List<TextFileHasher>();
string text1 = "abc\r\ncba\r\nabc";
TextFileHasher tfh1 = new TextFileHasher("Text1", new MemoryStream(System.Text.Encoding.Default.GetBytes(text1)));
tfh1.CalculateFileHash();
textFileHashers.Add(tfh1);
string text2 = "def\r\ncba\r\nwet";
TextFileHasher tfh2 = new TextFileHasher("Text2", new MemoryStream(System.Text.Encoding.Default.GetBytes(text2)));
tfh2.CalculateFileHash();
textFileHashers.Add(tfh2);
string text3 = "def\r\nbla\r\nwat";
TextFileHasher tfh3 = new TextFileHasher("Text3", new MemoryStream(System.Text.Encoding.Default.GetBytes(text3)));
tfh3.CalculateFileHash();
textFileHashers.Add(tfh3);
List<string> totalDuplicates = new List<string>();
Dictionary<ulong, Dictionary<TextFileHasher, List<LinePosition>>> totalHashes = new Dictionary<ulong, Dictionary<TextFileHasher, List<LinePosition>>>();
textFileHashers.ForEach(tfh => {
foreach(var dummyHash in tfh.Hashes) {
Dictionary<TextFileHasher, List<LinePosition>> tfh2LinePositions = null;
if (!totalHashes.TryGetValue(dummyHash, out tfh2LinePositions))
totalHashes[dummyHash] = new Dictionary<TextFileHasher, List<LinePosition>>() { { tfh, tfh.GetLinePositions(dummyHash) } };
else {
List<LinePosition> linePositions = null;
if (!tfh2LinePositions.TryGetValue(tfh, out linePositions))
tfh2LinePositions[tfh] = tfh.GetLinePositions(dummyHash);
else
linePositions.AddRange(tfh.GetLinePositions(dummyHash));
}
}
});
HashSet<TextFileHasher> alreadyGotDuplicates = new HashSet<TextFileHasher>();
foreach(var hash in totalHashes.Keys) {
var tfh2LinePositions = totalHashes[hash];
var tfh = tfh2LinePositions.Keys.FirstOrDefault();
// Get duplicates in the TextFileHasher itself
if (tfh != null && !alreadyGotDuplicates.Contains(tfh)) {
totalDuplicates.AddRange(tfh.GetDuplicates());
alreadyGotDuplicates.Add(tfh);
}
if (tfh2LinePositions.Count <= 1) {
continue;
}
// Algo to get duplicates in more than 1 TextFileHashers
var tfhs = tfh2LinePositions.Keys.ToArray();
for (int i = 0; i < tfhs.Length; i++) {
var tfh1Positions = tfhs[i].GetLinePositions(hash);
for (int j = i + 1; j < tfhs.Length; j++) {
var tfh2Positions = tfhs[j].GetLinePositions(hash);
for (int k = 0; k < tfh1Positions.Count; k++) {
var tfh1Pos = tfh1Positions[k];
var tfh1ByteArray = tfhs[i].GetLineAsByteArray(tfh1Pos);
for (int m = 0; m < tfh2Positions.Count; m++) {
var tfh2Pos = tfh2Positions[m];
if (tfh1Pos.Length != tfh2Pos.Length)
continue;
var tfh2ByteArray = tfhs[j].GetLineAsByteArray(tfh2Pos);
if (tfh1ByteArray.SequenceEqual(tfh2ByteArray)) {
var line = System.Text.Encoding.Default.GetString(tfh1ByteArray);
totalDuplicates.Add(line);
}
}
}
}
}
}
Console.WriteLine();
if (totalDuplicates.Count > 0) {
Console.WriteLine("Total number of duplicates: {0}", totalDuplicates.Count);
Console.WriteLine("#######################");
totalDuplicates.ForEach(x => Console.WriteLine("{0}", x));
Console.WriteLine("#######################");
}
// Free resources
foreach (var tfh in textFileHashers)
tfh.Dispose();
}
}

If you have tons of ram... You guys are overthinking it...
var fileLines = File.ReadAllLines(#"c:\file.csv").Distinct();

Postfix increment into if, c#

Code example:
using System;
public class Test {
public static void Main() {
int a = 0;
if(a++ == 0){
Console.WriteLine(a);
}
}
}
In this code the Console will write: 1. I can write this code in another way:
public static void Main() {
int a = 0;
if(a == 0){
a++;
Console.WriteLine(a);
}
}
These two examples work exactly the same (from what I know about postfix).
The problem is with this example coming from the Microsoft tutorials:
using System;
public class Document {
// Class allowing to view the document as an array of words:
public class WordCollection {
readonly Document document;
internal WordCollection (Document d){
document = d;
}
// Helper function -- search character array "text", starting
// at character "begin", for word number "wordCount". Returns
//false if there are less than wordCount words. Sets "start" and
//length to the position and length of the word within text
private bool GetWord(char[] text, int begin, int wordCount,
out int start, out int length) {
int end = text.Length;
int count = 0;
int inWord = -1;
start = length = 0;
for (int i = begin; i <= end; ++i){
bool isLetter = i < end && Char.IsLetterOrDigit(text[i]);
if (inWord >= 0) {
if (!isLetter) {
if (count++ == wordCount) {//PROBLEM IS HERE!!!!!!!!!!!!
start = inWord;
length = i - inWord;
return true;
}
inWord = -1;
}
} else {
if (isLetter) {
inWord = i;
}
}
}
return false;
}
//Indexer to get and set words of the containing document:
public string this[int index] {
get
{
int start, length;
if(GetWord(document.TextArray, 0, index, out start,
out length)) {
return new string(document.TextArray, start, length);
} else {
throw new IndexOutOfRangeException();
}
}
set {
int start, length;
if(GetWord(document.TextArray, 0, index, out start,
out length))
{
//Replace the word at start/length with
// the string "value"
if(length == value.Length){
Array.Copy(value.ToCharArray(), 0,
document.TextArray, start, length);
}
else {
char[] newText = new char[document.TextArray.Length +
value.Length - length];
Array.Copy(document.TextArray, 0, newText, 0, start);
Array.Copy(value.ToCharArray(), 0, newText, start, value.Length);
Array.Copy(document.TextArray, start + length, newText,
start + value.Length, document.TextArray.Length - start - length);
document.TextArray = newText;
}
} else {
throw new IndexOutOfRangeException();
}
}
}
public int Count {
get {
int count = 0, start = 0, length = 0;
while (GetWord(document.TextArray, start + length,
0, out start, out length)) {
++count;
}
return count;
}
}
}
// Class allowing the document to be viewed like an array
// of character
public class CharacterCollection {
readonly Document document;
internal CharacterCollection(Document d) {
document = d;
}
//Indexer to get and set character in the containing
//document
public char this[int index] {
get {
return document.TextArray[index];
}
set {
document.TextArray[index] = value;
}
}
//get the count of character in the containing document
public int Count {
get {
return document.TextArray.Length;
}
}
}
//Because the types of the fields have indexers,
//these fields appear as "indexed properties":
public WordCollection Words;
public readonly CharacterCollection Characters;
private char[] TextArray;
public Document(string initialText) {
TextArray = initialText.ToCharArray();
Words = new WordCollection(this);
Characters = new CharacterCollection(this);
}
public string Text {
get {
return new string(TextArray);
}
}
class Test {
static void Main() {
Document d = new Document(
"peter piper picked a peck of pickled peppers. How many pickled peppers did peter piper pick?"
);
//Change word "peter" to "penelope"
for(int i = 0; i < d.Words.Count; ++i){
if (d.Words[i] == "peter") {
d.Words[i] = "penelope";
}
}
for (int i = 0; i < d.Characters.Count; ++i) {
if (d.Characters[i] == 'p') {
d.Characters[i] = 'P';
}
}
Console.WriteLine(d.Text);
}
}
}
If I change the code marked above to this:
if (count == wordCount) {//PROBLEM IS HERE
start = inWord;
length = i - inWord;
count++;
return true;
}
I get an IndexOutOfRangeException, but I don't know why.

Your initial assumption is incorrect (that the two examples work exactly the same). In the following version, count is incremented regardless of whether or not it is equal to wordCount:
if (count++ == wordCount)
{
// Code omitted
}
In this version, count is ONLY incremented when it is equal to wordCount
if (count == wordCount)
{
// Other code omitted
count++;
}
EDIT
The reason this is causing you a failure is that, when you are searching for the second word (when wordCount is 1), the variable count will never equal wordCount (because it never gets incremented), and therefore the GetWord method returns false, which then triggers the else clause in your get method, which throws an IndexOutOfRangeException.

In your version of the code, count is only being incremented when count == wordCount; in the Microsoft version, it's being incremented whether the condition is met or not.

using System;
public class Test {
public static void Main() {
int a = 0;
if(a++ == 0){
Console.WriteLine(a);
}
}
}
Is not quite the same as:
public static void Main() {
int a = 0;
if(a == 0){
a++;
Console.WriteLine(a);
}
}
In the second case a++ is executed only if a == 0. In the first case a++ is executed every time we check the condition.

There is your mistake:
public static void Main() {
int a = 0;
if(a == 0){
a++;
Console.WriteLine(a);
}
}
It should be like this:
public static void Main() {
int a = 0;
if(a == 0){
a++;
Console.WriteLine(a);
}
else
a++;
}
a gets alwasy increased. This means, that in your code example count will get only increased when count == wordCount (In which case the method will return true anyway...). You basicly never increasing count.

How to use BeginInvoke

Ive got this problem:
Line 20 (LOOT_FromContainer(container) I need that to use as Invoke, because the process I want to exec takes some time, so ServerMessageHandler won't handle it...
If I just simply rewrite that line to LOOT_FromContainer.BeginInvoke(container); then I have this error:
error CS0119: 'LOOT.LOOT_FromContainer(Phoenix.Serial)' is a 'method',
which is not valid in the given context
I'm new to C#, came from PHP, and about Invoke I don't know much really. I've been trying to sort this out for a couple of days, not even google helped...
[ServerMessageHandler(0x3C)]
public CallbackResult ContainerContains(byte[] data, CallbackResult prevResult)
{
PacketReader reader = new PacketReader(data);
reader.Skip(3);
ushort len = reader.ReadUInt16();
for (int i = 0; i < len; i++)
{
Serial serial = (Serial)(reader.ReadUInt32());
ushort graphic = (ushort)(reader.ReadUInt16());
reader.Skip(7);
Serial container = (Serial)(reader.ReadUInt32());
ushort color = (ushort)(reader.ReadUInt16());
if (((int)graphic == 0x0E76) && ((int)color == 0x049A))
{
LOOT_FromContainer.BeginInvoke(container);
}
}
return CallbackResult.Normal;
}
[Command]
public static void LOOT_FromContainer(Serial target)
{
UOItem lootCorpse = new UOItem(target);
if (lootCorpse.Graphic == 0x2006)
{
if (((draw == 1) && (World.Player.Backpack.AllItems.Count(draw_knife[0], draw_knife[1]) > 0)) || (World.Player.Layers[Layer.RightHand].Exist))
{
if ((lootCorpse.Amount != 400) && (lootCorpse.Amount != 401))
{
if (draw == 0)
{
UO.WaitTargetObject(lootCorpse);
UO.UseObject(World.Player.Layers[Layer.RightHand].Serial);
}
else
{
UO.WaitTargetObject(lootCorpse);
UO.UseType(draw_knife[0], draw_knife[1]);
}
UO.Wait(500);
}
}
else
{
UO.Print("Neni cim rezat, pouze lootim");
}
for (int i = 0; i < loot.Length; i++)
{
if (lootCorpse.Items.Count(loot[i][0], loot[i][1]) > 0)
{
if (loot[i][2] == 1)
{
if (loot[i][4] == 1)
{
UO.MoveItem(lootCorpse.Items.FindType(loot[i][0], loot[i][1]), 0, Aliases.GetObject("loot_bag"), loot[i][5], loot[i][6]);
UO.Wait(200);
}
else
{
UO.MoveItem(lootCorpse.Items.FindType(loot[i][0], loot[i][1]), 0, World.Player.Backpack);
UO.Wait(200);
}
}
}
}
}
}

I think this is what you need. You need to declare a delegate with the same return type and input parameters as your method, instantiate this delegate pointing it at your method and then call BeginInvoke on it passing in your serial variable, followed by null, null:
public delegate void LFC(Serial target);
[ServerMessageHandler(0x3C)]
public CallbackResult ContainerContains(byte[] data, CallbackResult prevResult)
{
PacketReader reader = new PacketReader(data);
reader.Skip(3);
ushort len = reader.ReadUInt16();
for (int i = 0; i < len; i++)
{
Serial serial = (Serial)(reader.ReadUInt32());
ushort graphic = (ushort)(reader.ReadUInt16());
reader.Skip(7);
Serial container = (Serial)(reader.ReadUInt32());
ushort color = (ushort)(reader.ReadUInt16());
LFC = lootfromcontainer = new LFC(LOOT_FromContainer);
if (((int)graphic == 0x0E76) && ((int)color == 0x049A))
{
lootfromcontainer.BeginInvoke(container, null, null);
//LOOT_FromContainer.BeginInvoke(container);
}
}
return CallbackResult.Normal;
}
[Command]
public static void LOOT_FromContainer(Serial target)
{
UOItem lootCorpse = new UOItem(target);
if (lootCorpse.Graphic == 0x2006)
{
if (((draw == 1) && (World.Player.Backpack.AllItems.Count(draw_knife[0], draw_knife[1]) > 0)) || (World.Player.Layers[Layer.RightHand].Exist))
{
if ((lootCorpse.Amount != 400) && (lootCorpse.Amount != 401))
{
if (draw == 0)
{
UO.WaitTargetObject(lootCorpse);
UO.UseObject(World.Player.Layers[Layer.RightHand].Serial);
}
else
{
UO.WaitTargetObject(lootCorpse);
UO.UseType(draw_knife[0], draw_knife[1]);
}
UO.Wait(500);
}
}
else
{
UO.Print("Neni cim rezat, pouze lootim");
}
for (int i = 0; i < loot.Length; i++)
{
if (lootCorpse.Items.Count(loot[i][0], loot[i][1]) > 0)
{
if (loot[i][2] == 1)
{
if (loot[i][4] == 1)
{
UO.MoveItem(lootCorpse.Items.FindType(loot[i][0], loot[i][1]), 0, Aliases.GetObject("loot_bag"), loot[i][5], loot[i][6]);
UO.Wait(200);
}
else
{
UO.MoveItem(lootCorpse.Items.FindType(loot[i][0], loot[i][1]), 0, World.Player.Backpack);
UO.Wait(200);
}
}
}
}
}
}

If you simply need to run that in another thread you can use ThreadPool.
For this you would need few easy things:
Instead of:
LOOT_FromContainer.BeginInvoke(container);
You would use:
ThreadPool.QueueUserWorkItem(LOOT_FromContainer, container);
And slightly modify your LOOT_FromContainer method to:
public static void LOOT_FromContainer(object prm)
{
var target = (Serial)prm;
// ...

I'm assuming LOOT_FromCotainer is a control, and given the error your compiler returns, one can roughly guess the problem is that you're calling BeginInvoke with a non-delegate. BeginInvoke is called as follows:
LOOT_FromContainer.BeginInvoke(container); //where container is a delegate that maybe declared as follows
private delegate void container; //may also contain parameters eg container(string s);
So just rework your code to follow in this manner. See this document for example on how to use BeginInvoke.

Console animations

I just want to know how to create simple animations like blinking, moving stuffs on C# console applications. Is there any special method for this?

Traditional Console Spinner:
static void Main(string[] args)
{
ConsoleSpiner spin = new ConsoleSpiner();
Console.Write("Working....");
while (true)
{
spin.Turn();
}
}
public class ConsoleSpiner
{
int counter;
public ConsoleSpiner()
{
counter = 0;
}
public void Turn()
{
counter++;
switch (counter % 4)
{
case 0: Console.Write("/"); break;
case 1: Console.Write("-"); break;
case 2: Console.Write("\\"); break;
case 3: Console.Write("|"); break;
}
Console.SetCursorPosition(Console.CursorLeft - 1, Console.CursorTop);
}
}

Here is my spinner. The purpose of it is to have a program do some work while the spinner displays to the user that something is actually happening:
public class Spinner : IDisposable
{
private const string Sequence = #"/-\|";
private int counter = 0;
private readonly int left;
private readonly int top;
private readonly int delay;
private bool active;
private readonly Thread thread;
public Spinner(int left, int top, int delay = 100)
{
this.left = left;
this.top = top;
this.delay = delay;
thread = new Thread(Spin);
}
public void Start()
{
active = true;
if (!thread.IsAlive)
thread.Start();
}
public void Stop()
{
active = false;
Draw(' ');
}
private void Spin()
{
while (active)
{
Turn();
Thread.Sleep(delay);
}
}
private void Draw(char c)
{
Console.SetCursorPosition(left, top);
Console.ForegroundColor = ConsoleColor.Green;
Console.Write(c);
}
private void Turn()
{
Draw(Sequence[++counter % Sequence.Length]);
}
public void Dispose()
{
Stop();
}
}
And you use the class like this:
using (var spinner = new Spinner(10, 10))
{
spinner.Start();
// Do your work here instead of sleeping...
Thread.Sleep(10000);
}

Yes, there are quite a few methods for this.
In particular, you may want to look at the following Console methods:
SetCursorPosition (you can move the cursor around, and overwrite elements)
MoveBufferArea (copy/paste over the top of regions)
ForegroundColor and BackgroundColor (change coloring)

Great work with the ConsoleSpinner and the sequence implementation. Thanks for the code. I thought about sharing my customized approach.
public class ConsoleSpinner
{
static string[,] sequence = null;
public int Delay { get; set; } = 200;
int totalSequences = 0;
int counter;
public ConsoleSpinner()
{
counter = 0;
sequence = new string[,] {
{ "/", "-", "\\", "|" },
{ ".", "o", "0", "o" },
{ "+", "x","+","x" },
{ "V", "<", "^", ">" },
{ ". ", ".. ", "... ", "...." },
{ "=> ", "==> ", "===> ", "====>" },
// ADD YOUR OWN CREATIVE SEQUENCE HERE IF YOU LIKE
};
totalSequences = sequence.GetLength(0);
}
/// <summary>
///
/// </summary>
/// <param name="sequenceCode"> 0 | 1 | 2 |3 | 4 | 5 </param>
public void Turn(string displayMsg = "", int sequenceCode = 0)
{
counter++;
Thread.Sleep(Delay);
sequenceCode = sequenceCode > totalSequences - 1 ? 0 : sequenceCode;
int counterValue = counter % 4;
string fullMessage = displayMsg + sequence[sequenceCode, counterValue];
int msglength = fullMessage.Length;
Console.Write(fullMessage);
Console.SetCursorPosition(Console.CursorLeft - msglength, Console.CursorTop);
}
}
Implementation:
ConsoleSpinner spinner = new ConsoleSpinner();
spinner.Delay = 300;
while (true)
{
spinner.Turn(displayMsg: "Working ",sequenceCode:5);
}
Output:

You'll need to use Console.ForegroundColor, Console.BackgroundColor and Console.SetCursorPosition(int, int)
EDIT: For inspiration, Let's Dance

Just saw this and a few other threads about it and love this kind of stuff! I took Tuukka's nice piece of code and improved it a bit so the class can easily be set to just about any spin sequence. I'll probably add some accessors and an overloaded constructor to polish it off and put it in the ol' toolbox. Fun stuff!
class ConsoleSpinner
{
int counter;
string[] sequence;
public ConsoleSpinner()
{
counter = 0;
sequence = new string[] { "/", "-", "\\", "|" };
sequence = new string[] { ".", "o", "0", "o"};
sequence = new string[] { "+", "x" };
sequence = new string[] { "V", "<", "^", ">" };
sequence = new string[] { ". ", ".. ", "... ", "...." };
}
public void Turn()
{
counter++;
if (counter >= sequence.Length)
counter = 0;
Console.Write(sequence[counter]);
Console.SetCursorPosition(Console.CursorLeft - sequence[counter].Length, Console.CursorTop);
}
}

I took the anwser from #ThisGuy and modified it a bit, but I noticed, that sometimes the row is not cleared as it should.
static void Main(string[] args)
{
Console.WriteLine("1");
var tddf = XConsole.BusyIndicator("test 0 trtg fdfdfvdgd 4343", () =>
{
return "";
});
Console.WriteLine("2");
var tdd = XConsole.BusyIndicator("test 0 trtg fdfdfvdgd", () =>
{
Thread.Sleep(1);
return "";
});
Console.WriteLine("3");
var t = XConsole.BusyIndicator("test 1 trtg vdgd", () =>
{
Thread.Sleep(1000);
return "";
});
Console.WriteLine("4");
var xt = XConsole.BusyIndicator("test 2", () =>
{
Thread.Sleep(2000);
return "";
});
var xtx = XConsole.BusyIndicator("test 2 csds fsd fdsf ds s", () =>
{
Thread.Sleep(2000);
return "";
});
Console.WriteLine("5");
Thread.Sleep(4000);
}
Spinner class:
public class Spinner : IDisposable
{
private const string Sequence1 = #"/-\|";
private const string Sequence3 = #".o0o";
private const string Sequence2 = #"<^>v";
private const string Sequence4 = #"#■.";
private const string Sequence5 = #"▄▀";
private const string Sequence = #"└┘┐┌";
private string BusyMessage = "";
private int counter = 0;
private readonly int delay;
private bool active;
private readonly Thread thread;
public Spinner(int delay = 200)
{
this.delay = delay;
thread = new Thread(Spin);
}
public void Start()
{
active = true;
Console.CursorVisible = false;
if (!thread.IsAlive)
{
thread.Start();
}
}
public void Start(string busyMessage)
{
BusyMessage = busyMessage;
Start();
}
public void Stop()
{
active = false;
Console.CursorVisible = true;
ClearCurrentConsoleLine();
BusyMessage = "";
}
private static void ClearCurrentConsoleLine()
{
int currentLineCursor = Console.CursorTop;
Console.SetCursorPosition(0, Console.CursorTop);
Console.Write(new string(' ', Console.WindowWidth));
Console.SetCursorPosition(0, currentLineCursor);
}
private void Spin()
{
while (active)
{
Turn();
Thread.Sleep(delay);
}
}
/// <summary>
/// Draws the busy indicator
/// </summary>
/// <param name="c">if empty char, then clear screen</param>
private void Draw(char c)
{
int left = Console.CursorLeft;
int top = Console.CursorTop;
Console.Write('[');
Console.ForegroundColor = ConsoleColor.Green;
Console.Write(c);
Console.ForegroundColor = ConsoleColor.Gray;
Console.Write(']');
if (!string.IsNullOrEmpty(BusyMessage))
{
Console.Write(" " + BusyMessage);
}
//reset cursor position
Console.SetCursorPosition(left, top);
}
private void Turn()
{
Draw(Sequence[++counter % Sequence.Length]);
}
public void Dispose()
{
Stop();
}
}
My console class:
public static class XConsole {
public static T BusyIndicator<T>(Func<T> action)
{
T result;
using (var spinner = new Spinner())
{
spinner.Start();
result = action();
spinner.Stop();
}
return result;
}
public static T BusyIndicator<T>(string content, Func<T> action)
{
T result;
using (var spinner = new Spinner())
{
spinner.Start(content);
result = action();
spinner.Stop();
}
return result;
}
}
Why do I see this result sometimes?
1
2
3 st 0 trtg fdfdfvdgd ]
4
[└] test 2 csds fsd fdsf ds s
Looks like the Dispose didn't trigger? Or a new Task alredy started?
It should look like this:
1
2
3
4
[└] test 2 csds fsd fdsf ds s
UPDATE:
I added ClearCurrentConsoleLine(); and changed the Draw method, this fixed the issue.

i'm not TOO sure i know exactly what you're on about. but i'll give it a shot.
I think the biggest and best way to cause the "blinking" affect (or what i think the blinking affect is) is to use a carriage return.
The best way to explain it to you is to show you the Foo Bar experiment.
start a new project, and in your Main function, try this.
Console.WriteLine("Foo/nBar");
The output will look like this
Foo
Bar
But if you use a carriage return.
Console.WriteLine("Foo/rBar");
The output will look like this
Bar
The reason is that Foo is written, then the carriage return takes you BACK to the start of the line, then Bar is written. All you ever see is Bar.
This can be helpful for "Moving" things on one line, instead of rewriting the same things again on multiple lines.
A way to do progression would be to use Console.Write();
Try this.
Console.Write("Loading");
for(int i = 0; i < 10; i++)
{
Thread.Sleep(1000);
Console.Write(".");
}
The output should be
Loading
Followed by a Fullstop every second for 10 seconds.
If you combine the Carriage return with the Console.Write(); function you can write multiple things on a single line, clear the line and write something else, or indeed, the same thing just moved slightly. (This would of course need more than i have shown you, like recording where the "object" you are controlling is situated. If you would like a short example i would be happy to do one, just comment and ask me for it :)
Edit:
I noticed people mentioning colour, which i forgot. If you were doing animation i guess colour would be a must.
ForegroundColor and BackgroundColor are where it's at.
note that ForegroundColor will apply to the next characters written to the console, it will not completely recolour the Console.
/Edit
I hope this helps,
Skintkingle ;)

I thought I'd chime in with my version of the previously listed code. Here it is:
class ConsoleSpinner
{
bool increment = true,
loop = false;
int counter = 0;
int delay;
string[] sequence;
public ConsoleSpinner(string sSequence = "dots", int iDelay = 100, bool bLoop = false)
{
delay = iDelay;
if (sSequence == "dots")
{
sequence = new string[] { ". ", ".. ", "... ", "...." };
loop = true;
}
else if (sSequence == "slashes")
sequence = new string[] { "/", "-", "\\", "|" };
else if (sSequence == "circles")
sequence = new string[] { ".", "o", "0", "o" };
else if (sSequence == "crosses")
sequence = new string[] { "+", "x" };
else if (sSequence == "arrows")
sequence = new string[] { "V", "<", "^", ">" };
}
public void Turn()
{
if (loop)
{
if (counter >= sequence.Length - 1)
increment = false;
if (counter <= 0)
increment = true;
if (increment)
counter++;
else if (!increment)
counter--;
}
else
{
counter++;
if (counter >= sequence.Length)
counter = 0;
}
Console.Write(sequence[counter]);
Console.SetCursorPosition(Console.CursorLeft - sequence[counter].Length, Console.CursorTop);
System.Threading.Thread.Sleep(delay);
}
}
Adds delay (unfortunately through Thread.Sleep() but, hey), the ability to loop the animation forwards and backwards (starts to reverse when it hits the end), and general improvements overall. Enjoy!

This would be my prefered method:
public sealed class Spinner
{
private static Lazy<Spinner> lazy =
new Lazy<Spinner>(()=> new Spinner());
public static void Reset()
{
lazy = new Lazy<Spinner>(()=> new Spinner());
}
public static Spinner Instance { get { return lazy.Value; }}
private readonly int _consoleX;
private readonly int _consoleY;
private readonly char[] _frames = { '|', '/', '-', '\\' };
private int _current;
private Spinner()
{
_current = 0;
_consoleX = Console.CursorLeft;
_consoleY = Console.CursorTop;
}
public void Update()
{
Console.Write(_frames[_current]);
Console.SetCursorPosition(_consoleX, _consoleY);
if (++_current >= _frames.Length)
_current = 0;
}
}
Call Spinner.Instance.Update() to start the spinner at the current position of the console. Any consecutive call will render the next frame at the same position.
Call Spinner.Reset() if you want to write more text and then add a new spinner at a new location.

This is the way i solved it, sure it could/can be shorter but, Im just not that smart yet :-)
void cc() { Console.Clear(); }
void cr() { Console.ReadKey(); }
byte Sleeptimer = 90;
void sleepy() { System.Threading.Thread.Sleep(Sleeptimer); }
string[] Loading = { #"-- ", #"\ ", #"| ", #"/ ", "Loading", " complete!" };
for (byte i = 0; i <= 15; i++)
{
cc();
Console.ForegroundColor = ConsoleColor.Yellow;
Console.WriteLine(Loading[0] + Loading[4]);
sleepy();
cc();
Console.WriteLine(Loading[1] + Loading[4]);
sleepy();
cc();
Console.WriteLine(Loading[2] + Loading[4]);
sleepy();
cc();
Console.WriteLine(Loading[3] + Loading[4]);
sleepy();
cc();
if (i == 15) {
Console.ForegroundColor = ConsoleColor.Green;
Console.WriteLine(Loading[4] + Loading[5]);
cc();
Console.ForegroundColor = ConsoleColor.Cyan;
Next();
}
}
/*
Now i feel even more noob while reading your code.
I'm a newbie in programing.
Guess this way would work if i just incfement the index of each Loading down below right?
Learned too much today, forgot how this exactly works, to increment or to change the index i'd lile to acces
Console.WriteLine(Loading[2] + Loading[4]);
sleepy();
cc();
*/

This is animation with cancellationToken
private static void ClearCurrentConsoleLine()
{
int currentLineCursor = Console.CursorTop;
Console.SetCursorPosition(0, Console.CursorTop);
Console.Write(new string(' ', Console.WindowWidth));
Console.SetCursorPosition(0, currentLineCursor);
}
public static async Task Start(CancellationToken ct)
{
await Task.Run(() =>
{
Thread.Sleep(2000);
Console.WriteLine();
string text = "Executing";
for (int i = 0; i <= 3; i++)
{
if (ct.IsCancellationRequested)
{
Console.SetCursorPosition(0, Console.CursorTop - 1);
ClearCurrentConsoleLine();
ct.ThrowIfCancellationRequested();
}
Thread.Sleep(1000);
Console.SetCursorPosition(0, Console.CursorTop - 1);
ClearCurrentConsoleLine();
Console.WriteLine(text);
if (i == 3)
{
text = "Executing";
i = 0;
}
text += ".";
}
});
}```