How to test bounds of a bidimensional array, to avoid indexOutOfRangeException (C#) - c#

It's pretty simple to deal with an array with one dimension. But how can we avoid testing out of range locations within a bi dimensional array with different lengths on each row (jagged array)?
here is my code (if anyone wants to test):
static void Main(string[] args)
{
object[][] x = weirdReturn();
int k = 0;
while(x[0][k] != null) //THIS CODE PRODUCES THE EXCEPTION
{
for(int i = 0; i< x[k].Length; i++)
{
Console.Write("{0} ", x[k][i]);
}
Console.WriteLine("");
k++;
}
}
static object[][] weirdReturn()
{
DateTime d = new DateTime();
d = DateTime.Now;
object[] a2 = { 'X', 1.79, d, 100 };
object[] a1 = { 0, 'a', "objectX" };
object[][] retVal = new object[2][];
retVal[0] = a1;
retVal[1] = a2;
return retVal;
}

There is no magic to this - simply check the length and avoid indexing beyond that value minus one, as you would with a one-dimensional array.
Your code looks pretty messy, are you just trying to loop over the arrays like this?
static void Main(string[] args)
{
object[][] x = weirdReturn();
for (int i = 0; i < x.Length; i++)
{
for (int j = 0; j < x[i].Length; j++)
{
Console.Write("{0} ", x[i][j]);
}
Console.WriteLine("");
}
}
static object[][] weirdReturn()
{
DateTime d = new DateTime();
d = DateTime.Now;
object[] a2 = { 'X', 1.79, d, 100 };
object[] a1 = { 0, 'a', "objectX" };
object[][] retVal = new object[2][];
retVal[0] = a1;
retVal[1] = a2;
return retVal;
}

Related

Minimum element of each column in array of arrays

An array of arrays is given. It is necessary to find the minimum element in each column and write the data to a new array. I have done the following implementation, in accordance with the given conditions. But I am having a problem:expected minimum element in each column of the array are incorrect. Where am I making a mistake?
class Program
{
static int[][] Input()
{
Console.Write("n = ");
int n = int.Parse(Console.ReadLine());
int[][] a = new int[n][];
//int[] minA = new int[n];
for (int i = 0; i < n; ++i)
{
a[i] = new int[n];
for (int j = 0; j < n; ++j)
{
Console.Write("a[{0},{1}]= ", i, j);
a[i][j] = int.Parse(Console.ReadLine());
}
}
return a;
}
static void Print(int[] a)
{
foreach (double elem in a)
{
Console.Write("{0} ", elem);
}
}
static void Print2(int[][] a)
{
for (int i = 0; i < a.Length; ++i, Console.WriteLine())
for (int j = 0; j < a[i].Length; ++j)
Console.Write("{0,5} ", a[i][j]);
}
static int[] F(int[][] a)
{
int[] b = new int[a[1].Length];
for (int j = 0; j < a[1].Length; j++)
{
int tempmin = a[0][j];
for (int i = 0; i < a[0].Length; i++)
{
if (a[j][i] <= tempmin)
{
tempmin = a[j][i];
b[j] += tempmin;
}
}
}
return b;
}
static void Main()
{
int[][] myArray = Input();
Print2(myArray);
int[] b = new int[myArray.Length];
b = F(myArray);
Print(b);
}
}
I suggest looping over all lines, while tracking all min columns values:
using System.Linq; // for the final `ToArray()`
...
private static int[] MinColumns(int[][] data) {
if (null == data)
throw new ArgumentNullException(nameof(data));
// List of columns' mins; initially the list is empty
List<int> list = new List<int>();
// for each line (not column!) within jagged array...
foreach (int[] line in data) {
// let's just skip null lines (alternative is to throw exception)
if (null == line)
continue;
// each new line can update columns' max values.
// now we update each column
for (int c = 0; c < line.Length; ++c)
// if index c is too big, i.e.
// the line is too long and some columns appear first time...
if (c >= list.Count)
// ...we just add values of such columns as columns' min
for (int i = list.Count; i <= c; ++i)
list.Add(line[i]);
else
// otherwise we update min values: we compare known min and current value
list[c] = Math.Min(list[c], line[c]);
}
// finally, we convert list into array with ahelp of Linq
return list.ToArray();
}
Note, that here we ignore all holes, e.g. for
int[][] demo = new int[][] {
new int[] {1, 2, 3, 4},
new int[] {5, 6}, // <- hole: we don't have 3d and 4th columns here
new int[] {7, 0, 8},
};
the answer will be {Min(1, 5, 7), Min(2, 6, 0), Min(3, 8), Min (4)} = {1, 0, 3, 4}
Edit: Usage is quite direct; something like this (fiddle yourself)
static void Main()
{
// Get jagged array
int[][] myArray = Input();
// Print it
Print2(myArray);
// Get max for each column
int[] b = MinColumns(myArray);
// Print these maxes
Print(b);
}

How to convert a 2D object array to a 2D string array in C#?

I have a 2D array of objects called 'value'. I want to convert it to a 2D string array. How do I do this?
object value; //This is a 2D array of objects
string prop[,]; //This is a 2D string
If possible I would also like to know if I can convert the object to
List<List<string>>
directly.
Is this what you are looking for?
string[,] prop; //This is a 2D string
List<List<string>> mysteryList;
if (value is object[,])
{
object[,] objArray = (object[,])value;
// Get upper bounds for the array
int bound0 = objArray.GetUpperBound(0);//index of last element for the given dimension
int bound1 = objArray.GetUpperBound(1);
prop = new string[bound0 + 1, bound1 + 1];
mysteryList = new List<List<string>>();
for (int i = 0; i <= bound0; i++)
{
var temp = new List<string>();
for (int j = 0; j <= bound1; j++)
{
prop[i, j] = objArray[i, j].ToString();//Do null check and assign
temp.Add(prop[i, j]);
}
mysteryList.Add(temp);
}
}
To answer your first question you can achieve the conversion to a 2D string array with this:
List<string[]> objectValues = new List<string[]>
{
new[] { "1", "2", "3" },
new[] { "A", "B", "C" },
};
string[,] prop = ConvertObjectListArray(objectValues );
public T[,] ConvertObjectListArray<T>(IList<T[]> objectList)
{
int Length2 = objectList[0].Length;
T[,] ret = new T[objectList.Count, Length2];
for (int i = 0; i < objectList.Count; i++)
{
var array = objectList[i];
if (array.Length != Length2)
{
throw new ArgumentException
("All arrays must be the same length");
}
for (int i2 = 0; i2 < Length2; i2++)
{
ret[i, i2] = array[i2];
}
}
return ret;
}

How can I scatter an object array using MPI.NET

I'm trying to scatter a 2d boxed array.
here is the summerized code:
using (new MPI.Environment(ref args))
{
Intracommunicator comm = Communicator.world;
object[] boxedArrays = new object[] { };
if (comm.Rank == 0)
{
[... //some initialization ]
boxedArrays = new object[comm.size];
for (int p = 0; p < comm.Size; p++)
{
[... //some code to init the array]
boxedArrays[p] = array;
}
}
object myChunk= comm.Scatter(boxedArrays, 0);
var myArray = (int[,])myChunk;
}
When I print myArray it's empty.I tried the other variation of the scatter method but they also didn't work.
I'm using mpi.net sdk with Microsoft HPC Pack 2012.
Scattering messages in MPI.NET
An array of integers is scattered to all ranks, from the rank 0:
class Program
{
static void Main(string[] args)
{
using (MPI.Environment environment = new MPI.Environment(ref args))
{
Intracommunicator comm = Communicator.world;
if (comm.Rank == 0)
{
int [] numbers = new int[comm.Size];
for (int k = 0; k < numbers.Length; k++)
numbers[k] = k * k;
int r = comm.Scatter(numbers);
Console.WriteLine("Received {0} at {1}", r, comm.Rank);
}
else
{
int r = comm.Scatter<int>(0);
Console.WriteLine("Received {0} at {1}", r, comm.Rank);
}
}
}
}

Generic initialization of multidimensional array

I have a multidimensional array, which I want to initialize in a simple and fast way:
double[,,] arr = new double[4,5,6];
// doesn't work by design
foreach(double d in arr)
d = ... ; // my initialization value
This obviously doesn't works. But I would like to have a generic function for setting all array values to a choosen default. With own classes, I could write a special constructor, but with value types I've no real idea. With C++, I could access all items in a linear way with one for loop, but in C# I think I've to use as much for loops as I have dimensions. I've no better solution at the moment ( or I'm using unsafe code and pointer arithmetics, which would probably work.).
Is there a more elegant way for doing this ?
Not quite sure if it's what you want, but the following extension method will allow you to initialise every value in an array, regardless of the number of dimensions.
public static class ArrayExtensions
{
public static void Set<T>(this Array array, T defaultValue)
{
int[] indicies = new int[array.Rank];
SetDimension<T>(array, indicies, 0, defaultValue);
}
private static void SetDimension<T>(Array array, int[] indicies, int dimension, T defaultValue)
{
for (int i = 0; i <= array.GetUpperBound(dimension); i++)
{
indicies[dimension] = i;
if (dimension < array.Rank - 1)
SetDimension<T>(array, indicies, dimension + 1, defaultValue);
else
array.SetValue(defaultValue, indicies);
}
}
}
Use like so:
int[, ,] test1 = new int[3, 4, 5];
test1.Set(1);
int[,] test2 = new int[3, 4];
test2.Set(1);
int[] test3 = new int[3];
test3.Set(1);
I would strongly recommend using a 1D array, and map the values sequentially. You will need to convert from indeces i, j, k, ... into the proper array index, which is done with the Que() function below, part of a generic array class SeqArray<T>.
// Test code first
class Program
{
static void Main(string[] args)
{
/* 3 pages, of a 4x2 matrix
*
* |16 17|
* | 8 9|19|
* | 0 1|11|21|
* | 2 3|13|23|
* | 4 5|15|
* | 6 7|
*
* shown above are the sequential indeces for a rank 3 array
*/
SeqArray<double> arr = new SeqArray<double>(3, 4, 2);
// Initialize values to squential index "num"
int num = 0;
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 4; j++)
{
for (int k = 0; k < 2; k++)
{
arr[i, j, k] = num++;
}
}
}
// Check that the array values correspond to the index sequence
num = 0;
for (int i = 0; i < 3 * 4 * 2; i++)
{
Trace.Assert(arr.InnerArray[i] == num++);
}
// Initialize with value=π
arr = new SeqArray<double>(Math.PI, 4, 5, 6);
}
}
public class SeqArray<T>
{
T[] values;
int[] lengths;
public SeqArray(params int[] lengths)
{
this.lengths = lengths;
int N = 1;
for (int i = 0; i < lengths.Length; i++)
{
N *= lengths[i];
}
values = new T[N];
}
public SeqArray(T value, params int[] lengths) : this(lengths)
{
for (int i = 0; i < values.Length; i++)
{
values[i] = value;
}
}
public int[] Lengths { get { return lengths; } }
public int Size { get { return values.Length; } }
internal T[] InnerArray { get { return values; } }
public int Que(params int[] indeces)
{
// Check if indeces are omited like arr[4] instead of arr[4,0,0]
if (indeces.Length < lengths.Length)
{
// Make a new index array padded with zeros
int[] temp = new int[lengths.Length];
indeces.CopyTo(temp, 0);
indeces = temp;
}
// Count the elements for indeces
int k = 0;
for (int i = 0; i < indeces.Length; i++)
{
k = lengths[i] * k + indeces[i];
}
return k;
}
public T this[params int[] indeces]
{
get { return values[Que(indeces)]; }
set { values[Que(indeces)] = value; }
}
}
Here is a non-recursive version alternative to that posted by Andy Holt above:
public static void SetAll<T>(this Array array, T value)
{
var sizes = new int[array.Rank];
sizes[array.Rank - 1] = 1;
for (var d = array.Rank - 2; d >= 0; d--)
{
sizes[d] = array.GetLength(d + 1)*sizes[d + 1];
}
for (var i = 0; i < array.Length; i++)
{
var remainder = i;
var index = new int[array.Rank];
for (var d = 0; d < array.Rank && remainder > 0; d++)
{
index[d] = remainder / sizes[d];
remainder -= index[d]*sizes[d];
}
array.SetValue(value, index);
}
}

How do I remove duplicates from a C# array?

I have been working with a string[] array in C# that gets returned from a function call. I could possibly cast to a Generic collection, but I was wondering if there was a better way to do it, possibly by using a temp array.
What is the best way to remove duplicates from a C# array?
You could possibly use a LINQ query to do this:
int[] s = { 1, 2, 3, 3, 4};
int[] q = s.Distinct().ToArray();
Here is the HashSet<string> approach:
public static string[] RemoveDuplicates(string[] s)
{
HashSet<string> set = new HashSet<string>(s);
string[] result = new string[set.Count];
set.CopyTo(result);
return result;
}
Unfortunately this solution also requires .NET framework 3.5 or later as HashSet was not added until that version. You could also use array.Distinct(), which is a feature of LINQ.
The following tested and working code will remove duplicates from an array. You must include the System.Collections namespace.
string[] sArray = {"a", "b", "b", "c", "c", "d", "e", "f", "f"};
var sList = new ArrayList();
for (int i = 0; i < sArray.Length; i++) {
if (sList.Contains(sArray[i]) == false) {
sList.Add(sArray[i]);
}
}
var sNew = sList.ToArray();
for (int i = 0; i < sNew.Length; i++) {
Console.Write(sNew[i]);
}
You could wrap this up into a function if you wanted to.
If you needed to sort it, then you could implement a sort that also removes duplicates.
Kills two birds with one stone, then.
This might depend on how much you want to engineer the solution - if the array is never going to be that big and you don't care about sorting the list you might want to try something similar to the following:
public string[] RemoveDuplicates(string[] myList) {
System.Collections.ArrayList newList = new System.Collections.ArrayList();
foreach (string str in myList)
if (!newList.Contains(str))
newList.Add(str);
return (string[])newList.ToArray(typeof(string));
}
List<String> myStringList = new List<string>();
foreach (string s in myStringArray)
{
if (!myStringList.Contains(s))
{
myStringList.Add(s);
}
}
This is O(n^2), which won't matter for a short list which is going to be stuffed into a combo, but could be rapidly be a problem on a big collection.
-- This is Interview Question asked every time. Now i done its coding.
static void Main(string[] args)
{
int[] array = new int[] { 4, 8, 4, 1, 1, 4, 8 };
int numDups = 0, prevIndex = 0;
for (int i = 0; i < array.Length; i++)
{
bool foundDup = false;
for (int j = 0; j < i; j++)
{
if (array[i] == array[j])
{
foundDup = true;
numDups++; // Increment means Count for Duplicate found in array.
break;
}
}
if (foundDup == false)
{
array[prevIndex] = array[i];
prevIndex++;
}
}
// Just Duplicate records replce by zero.
for (int k = 1; k <= numDups; k++)
{
array[array.Length - k] = '\0';
}
Console.WriteLine("Console program for Remove duplicates from array.");
Console.Read();
}
Here is a O(n*n) approach that uses O(1) space.
void removeDuplicates(char* strIn)
{
int numDups = 0, prevIndex = 0;
if(NULL != strIn && *strIn != '\0')
{
int len = strlen(strIn);
for(int i = 0; i < len; i++)
{
bool foundDup = false;
for(int j = 0; j < i; j++)
{
if(strIn[j] == strIn[i])
{
foundDup = true;
numDups++;
break;
}
}
if(foundDup == false)
{
strIn[prevIndex] = strIn[i];
prevIndex++;
}
}
strIn[len-numDups] = '\0';
}
}
The hash/linq approaches above are what you would generally use in real life. However in interviews they usually want to put some constraints e.g. constant space which rules out hash or no internal api - which rules out using LINQ.
protected void Page_Load(object sender, EventArgs e)
{
string a = "a;b;c;d;e;v";
string[] b = a.Split(';');
string[] c = b.Distinct().ToArray();
if (b.Length != c.Length)
{
for (int i = 0; i < b.Length; i++)
{
try
{
if (b[i].ToString() != c[i].ToString())
{
Response.Write("Found duplicate " + b[i].ToString());
return;
}
}
catch (Exception ex)
{
Response.Write("Found duplicate " + b[i].ToString());
return;
}
}
}
else
{
Response.Write("No duplicate ");
}
}
Add all the strings to a dictionary and get the Keys property afterwards. This will produce each unique string, but not necessarily in the same order your original input had them in.
If you require the end result to have the same order as the original input, when you consider the first occurance of each string, use the following algorithm instead:
Have a list (final output) and a dictionary (to check for duplicates)
For each string in the input, check if it exists in the dictionary already
If not, add it both to the dictionary and to the list
At the end, the list contains the first occurance of each unique string.
Make sure you consider things like culture and such when constructing your dictionary, to make sure you handle duplicates with accented letters correctly.
The following piece of code attempts to remove duplicates from an ArrayList though this is not an optimal solution. I was asked this question during an interview to remove duplicates through recursion, and without using a second/temp arraylist:
private void RemoveDuplicate()
{
ArrayList dataArray = new ArrayList(5);
dataArray.Add("1");
dataArray.Add("1");
dataArray.Add("6");
dataArray.Add("6");
dataArray.Add("6");
dataArray.Add("3");
dataArray.Add("6");
dataArray.Add("4");
dataArray.Add("5");
dataArray.Add("4");
dataArray.Add("1");
dataArray.Sort();
GetDistinctArrayList(dataArray, 0);
}
private void GetDistinctArrayList(ArrayList arr, int idx)
{
int count = 0;
if (idx >= arr.Count) return;
string val = arr[idx].ToString();
foreach (String s in arr)
{
if (s.Equals(arr[idx]))
{
count++;
}
}
if (count > 1)
{
arr.Remove(val);
GetDistinctArrayList(arr, idx);
}
else
{
idx += 1;
GetDistinctArrayList(arr, idx);
}
}
Simple solution:
using System.Linq;
...
public static int[] Distinct(int[] handles)
{
return handles.ToList().Distinct().ToArray();
}
Maybe hashset which do not store duplicate elements and silently ignore requests to add
duplicates.
static void Main()
{
string textWithDuplicates = "aaabbcccggg";
Console.WriteLine(textWithDuplicates.Count());
var letters = new HashSet<char>(textWithDuplicates);
Console.WriteLine(letters.Count());
foreach (char c in letters) Console.Write(c);
Console.WriteLine("");
int[] array = new int[] { 12, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2 };
Console.WriteLine(array.Count());
var distinctArray = new HashSet<int>(array);
Console.WriteLine(distinctArray.Count());
foreach (int i in distinctArray) Console.Write(i + ",");
}
NOTE : NOT tested!
string[] test(string[] myStringArray)
{
List<String> myStringList = new List<string>();
foreach (string s in myStringArray)
{
if (!myStringList.Contains(s))
{
myStringList.Add(s);
}
}
return myStringList.ToString();
}
Might do what you need...
EDIT Argh!!! beaten to it by rob by under a minute!
Tested the below & it works. What's cool is that it does a culture sensitive search too
class RemoveDuplicatesInString
{
public static String RemoveDups(String origString)
{
String outString = null;
int readIndex = 0;
CompareInfo ci = CultureInfo.CurrentCulture.CompareInfo;
if(String.IsNullOrEmpty(origString))
{
return outString;
}
foreach (var ch in origString)
{
if (readIndex == 0)
{
outString = String.Concat(ch);
readIndex++;
continue;
}
if (ci.IndexOf(origString, ch.ToString().ToLower(), 0, readIndex) == -1)
{
//Unique char as this char wasn't found earlier.
outString = String.Concat(outString, ch);
}
readIndex++;
}
return outString;
}
static void Main(string[] args)
{
String inputString = "aAbcefc";
String outputString;
outputString = RemoveDups(inputString);
Console.WriteLine(outputString);
}
}
--AptSenSDET
This code 100% remove duplicate values from an array[as I used a[i]].....You can convert it in any OO language..... :)
for(int i=0;i<size;i++)
{
for(int j=i+1;j<size;j++)
{
if(a[i] == a[j])
{
for(int k=j;k<size;k++)
{
a[k]=a[k+1];
}
j--;
size--;
}
}
}
Generic Extension method :
public static IEnumerable<TSource> Distinct<TSource>(this IEnumerable<TSource> source, IEqualityComparer<TSource> comparer)
{
if (source == null)
throw new ArgumentNullException(nameof(source));
HashSet<TSource> set = new HashSet<TSource>(comparer);
foreach (TSource item in source)
{
if (set.Add(item))
{
yield return item;
}
}
}
you can using This code when work with an ArrayList
ArrayList arrayList;
//Add some Members :)
arrayList.Add("ali");
arrayList.Add("hadi");
arrayList.Add("ali");
//Remove duplicates from array
for (int i = 0; i < arrayList.Count; i++)
{
for (int j = i + 1; j < arrayList.Count ; j++)
if (arrayList[i].ToString() == arrayList[j].ToString())
arrayList.Remove(arrayList[j]);
Below is an simple logic in java you traverse elements of array twice and if you see any same element you assign zero to it plus you don't touch the index of element you are comparing.
import java.util.*;
class removeDuplicate{
int [] y ;
public removeDuplicate(int[] array){
y=array;
for(int b=0;b<y.length;b++){
int temp = y[b];
for(int v=0;v<y.length;v++){
if( b!=v && temp==y[v]){
y[v]=0;
}
}
}
}
public static int RemoveDuplicates(ref int[] array)
{
int size = array.Length;
// if 0 or 1, return 0 or 1:
if (size < 2) {
return size;
}
int current = 0;
for (int candidate = 1; candidate < size; ++candidate) {
if (array[current] != array[candidate]) {
array[++current] = array[candidate];
}
}
// index to count conversion:
return ++current;
}
The best way? Hard to say, the HashSet approach looks fast,
but (depending on the data) using a sort algorithm (CountSort ?)
can be much faster.
using System;
using System.Collections.Generic;
using System.Linq;
class Program
{
static void Main()
{
Random r = new Random(0); int[] a, b = new int[1000000];
for (int i = b.Length - 1; i >= 0; i--) b[i] = r.Next(b.Length);
a = new int[b.Length]; Array.Copy(b, a, b.Length);
a = dedup0(a); Console.WriteLine(a.Length);
a = new int[b.Length]; Array.Copy(b, a, b.Length);
var w = System.Diagnostics.Stopwatch.StartNew();
a = dedup0(a); Console.WriteLine(w.Elapsed); Console.Read();
}
static int[] dedup0(int[] a) // 48 ms
{
return new HashSet<int>(a).ToArray();
}
static int[] dedup1(int[] a) // 68 ms
{
Array.Sort(a); int i = 0, j = 1, k = a.Length; if (k < 2) return a;
while (j < k) if (a[i] == a[j]) j++; else a[++i] = a[j++];
Array.Resize(ref a, i + 1); return a;
}
static int[] dedup2(int[] a) // 8 ms
{
var b = new byte[a.Length]; int c = 0;
for (int i = 0; i < a.Length; i++)
if (b[a[i]] == 0) { b[a[i]] = 1; c++; }
a = new int[c];
for (int j = 0, i = 0; i < b.Length; i++) if (b[i] > 0) a[j++] = i;
return a;
}
}
Almost branch free. How? Debug mode, Step Into (F11) with a small array: {1,3,1,1,0}
static int[] dedupf(int[] a) // 4 ms
{
if (a.Length < 2) return a;
var b = new byte[a.Length]; int c = 0, bi, ai, i, j;
for (i = 0; i < a.Length; i++)
{ ai = a[i]; bi = 1 ^ b[ai]; b[ai] |= (byte)bi; c += bi; }
a = new int[c]; i = 0; while (b[i] == 0) i++; a[0] = i++;
for (j = 0; i < b.Length; i++) a[j += bi = b[i]] += bi * i; return a;
}
A solution with two nested loops might take some time,
especially for larger arrays.
static int[] dedup(int[] a)
{
int i, j, k = a.Length - 1;
for (i = 0; i < k; i++)
for (j = i + 1; j <= k; j++) if (a[i] == a[j]) a[j--] = a[k--];
Array.Resize(ref a, k + 1); return a;
}
private static string[] distinct(string[] inputArray)
{
bool alreadyExists;
string[] outputArray = new string[] {};
for (int i = 0; i < inputArray.Length; i++)
{
alreadyExists = false;
for (int j = 0; j < outputArray.Length; j++)
{
if (inputArray[i] == outputArray[j])
alreadyExists = true;
}
if (alreadyExists==false)
{
Array.Resize<string>(ref outputArray, outputArray.Length + 1);
outputArray[outputArray.Length-1] = inputArray[i];
}
}
return outputArray;
}
int size = a.Length;
for (int i = 0; i < size; i++)
{
for (int j = i + 1; j < size; j++)
{
if (a[i] == a[j])
{
for (int k = j; k < size; k++)
{
if (k != size - 1)
{
int temp = a[k];
a[k] = a[k + 1];
a[k + 1] = temp;
}
}
j--;
size--;
}
}
}
So I was doing an interview session and got the same question to sort and distinct
static void Sort()
{
try
{
int[] number = new int[Convert.ToInt32(Console.ReadLine())];
for (int i = 0; i < number.Length; i++)
{
number[i] = Convert.ToInt32(Console.ReadLine());
}
Array.Sort(number);
int[] num = number.Distinct().ToArray();
for (int i = 0; i < num.Length; i++)
{
Console.WriteLine(num[i]);
}
}
catch (Exception ex)
{
Console.WriteLine(ex);
}
Console.Read();
}
using System;
using System.Collections.Generic;
using System.Linq;
namespace Rextester
{
public class Program
{
public static void Main(string[] args)
{
List<int> listofint1 = new List<int> { 4, 8, 4, 1, 1, 4, 8 };
List<int> updatedlist= removeduplicate(listofint1);
foreach(int num in updatedlist)
Console.WriteLine(num);
}
public static List<int> removeduplicate(List<int> listofint)
{
List<int> listofintwithoutduplicate= new List<int>();
foreach(var num in listofint)
{
if(!listofintwithoutduplicate.Any(p=>p==num))
{
listofintwithoutduplicate.Add(num);
}
}
return listofintwithoutduplicate;
}
}
}
strINvalues = "1,1,2,2,3,3,4,4";
strINvalues = string.Join(",", strINvalues .Split(',').Distinct().ToArray());
Debug.Writeline(strINvalues);
Kkk Not sure if this is witchcraft or just beautiful code
1 strINvalues .Split(',').Distinct().ToArray()
2 string.Join(",", XXX);
1 Splitting the array and using Distinct [LINQ] to remove duplicates
2 Joining it back without the duplicates.
Sorry I never read the text on StackOverFlow just the code. it make more sense than the text ;)
Removing duplicate and ignore case sensitive using Distinct & StringComparer.InvariantCultureIgnoreCase
string[] array = new string[] { "A", "a", "b", "B", "a", "C", "c", "C", "A", "1" };
var r = array.Distinct(StringComparer.InvariantCultureIgnoreCase).ToList();
Console.WriteLine(r.Count); // return 4 items
Find answer below.
class Program
{
static void Main(string[] args)
{
var nums = new int[] { 1, 4, 3, 3, 3, 5, 5, 7, 7, 7, 7, 9, 9, 9 };
var result = removeDuplicates(nums);
foreach (var item in result)
{
Console.WriteLine(item);
}
}
static int[] removeDuplicates(int[] nums)
{
nums = nums.ToList().OrderBy(c => c).ToArray();
int j = 1;
int i = 0;
int stop = 0;
while (j < nums.Length)
{
if (nums[i] != nums[j])
{
nums[i + 1] = nums[j];
stop = i + 2;
i++;
}
j++;
}
nums = nums.Take(stop).ToArray();
return nums;
}
}
Just a bit of contribution based on a test i just solved, maybe helpful and open to improvement by other top contributors here.
Here are the things i did:
I used OrderBy which allows me order or sort the items from smallest to the highest using LINQ
I then convert it to back to an array and then re-assign it back to the primary datasource
So i then initialize j which is my right hand side of the array to be 1 and i which is my left hand side of the array to be 0, i also initialize where i would i to stop to be 0.
I used a while loop to increment through the array by going from one position to the other left to right, for each increment the stop position is the current value of i + 2 which i will use later to truncate the duplicates from the array.
I then increment by moving from left to right from the if statement and from right to right outside of the if statement until i iterate through the entire values of the array.
I then pick from the first element to the stop position which becomes the last i index plus 2. that way i am able to remove all the duplicate items from the int array. which is then reassigned.

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