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Reduce execution time c# algorithm

I'm solving Kattis' bokforing problem and one of the test cases fails due to execution time being too long (> 2 sec). Can anyone give me any advice on how I can improve?
class Program
{
static void Main(string[] args)
{
/* Inputs
3 5
SET 1 7
PRINT 1
PRINT 2
RESTART 33
PRINT 1
*/
string first = Console.ReadLine();
int N = Convert.ToInt32(first.Split(" ")[0]);
int Q = Convert.ToInt32(first.Split(" ")[1]);
int[] Accounts = new int[N];
string[] Operations = new string[Q];
for (int i = 0; i < Operations.Length; i++)
{
Operations[i] = Console.ReadLine();
}
for (int i = 0; i < Operations.Length; i++)
{
string[] op = Operations[i].Split(" ");
string operation = op[0];
int accountId = 0;
int ammont = 0;
if (operation == "SET")
{
accountId = Convert.ToInt32(op[1]);
ammont = Convert.ToInt16(op[2]);
Accounts[accountId - 1] = ammont;
}
if (operation == "PRINT")
{
accountId = Convert.ToInt32(op[1]);
Console.WriteLine(Accounts[accountId - 1]);
}
if (operation == "RESTART")
{
ammont = Convert.ToInt16(op[1]);
for (int j = 0; j <= N - 1; j++)
{
Accounts[j] = ammont;
}
}
}
}
}

First of all I copied recommended IO classes from FAQ to the solution, removed double loop (there is no need to loop twice - reading inputs first and then processing them) and then the main trick was to use Dictionary instead of array so there is no need to manually clear it/set amount to all items in it every time:
var scanner = new Scanner();
using(var writer = new BufferedStdoutWriter())
{
var N = scanner.NextInt();
var Q = scanner.NextInt();
var amount = 0;
var Accounts = new Dictionary<int, int>();
for (var i = 0; i < Q; i++)
{
var s = scanner.Next();
var accountId = 0;
if (s == "SET")
{
accountId = scanner.NextInt();
Accounts[accountId] = scanner.NextInt();
}
else if (s == "PRINT")
{
accountId = scanner.NextInt();
if (!Accounts.TryGetValue(accountId, out var value))
{
value = amount;
}
writer.WriteLine(value);
}
else if (s == "RESTART")
{
amount = scanner.NextInt();
Accounts = new Dictionary<int, int>();
}
}
}

Function Anagram

An anagram is a word formed from another by rearranging its letters, using all the original letters exactly once; for example, orchestra can be rearranged into carthorse.
I want to write a function to return all anagrams of a given word (including the word itself) in any order.
For example GetAllAnagrams("abba") should return a collection containing "aabb", "abab", "abba", "baab", "baba", "bbaa".
Any help would be appreciated.

Here is a working function, making use of a GetPermutations() extension found elsewhere on stack overflow
public static List<string> GetAnagrams(string word)
{
HashSet<string> anagrams = new HashSet<string>();
char[] characters = word.ToCharArray();
foreach (IEnumerable<char> permutation in characters.GetPermutations())
{
anagrams.Add(new String(permutation.ToArray()));
}
return anagrams.OrderBy(x => x).ToList();
}
Here is the GetPermutations() extension and it's other necessary extensions:
public static IEnumerable<IEnumerable<T>> GetPermutations<T>(this IEnumerable<T> enumerable)
{
var array = enumerable as T[] ?? enumerable.ToArray();
var factorials = Enumerable.Range(0, array.Length + 1)
.Select(Factorial)
.ToArray();
for (var i = 0L; i < factorials[array.Length]; i++)
{
var sequence = GenerateSequence(i, array.Length - 1, factorials);
yield return GeneratePermutation(array, sequence);
}
}
private static IEnumerable<T> GeneratePermutation<T>(T[] array, IReadOnlyList<int> sequence)
{
var clone = (T[])array.Clone();
for (int i = 0; i < clone.Length - 1; i++)
{
Swap(ref clone[i], ref clone[i + sequence[i]]);
}
return clone;
}
private static int[] GenerateSequence(long number, int size, IReadOnlyList<long> factorials)
{
var sequence = new int[size];
for (var j = 0; j < sequence.Length; j++)
{
var facto = factorials[sequence.Length - j];
sequence[j] = (int)(number / facto);
number = (int)(number % facto);
}
return sequence;
}
static void Swap<T>(ref T a, ref T b)
{
T temp = a;
a = b;
b = temp;
}
private static long Factorial(int n)
{
long result = n;
for (int i = 1; i < n; i++)
{
result = result * i;
}
return result;
}
}
Here is a screenshot of the result:
And, finally, a github repository of the complete Visual Studio solution: Github

import java.util.Scanner;
import java.lang.String;
public class KrishaAnagram
{
public static void main(String[] args) {
Scanner Scan = new Scanner(System.in);
String s1, s2;
int sum1, sum2;
sum1 = sum2 = 0;
System.out.print("Enter fisrt string: ");
s1 = Scan.next();
System.out.print("Enter Second string: ");
s2 = Scan.next();
if (s1.length() != s2.length()) {
System.out.println("NOT ANAGRAM");
} else {
for (int i = 0; i < s1.length(); i++) {
char ch1 = s1.charAt(i);
char ch2 = s2.charAt(i);
sum1 += (int) ch1;
sum2 += (int) ch2;
}
if (sum1 == sum2)
System.out.println("IT IS AN ANAGRAM : s1 = " + sum1 + "s1 = " + sum2);
else
System.out.println("IT IS NOT AN ANAGRAM : s1 = " + sum1 + "s1 = " + sum2);;
}
}
}
//This is My way of solving anagram in java,Hope it helps.

How to add or subtract very large numbers without bigint in C#?

So let me start by saying that I'm a newbie with little to moderate knowledge about C#.
Coming to the topic: I need to make a program that is able to add/subtract very large integers. Initially, used BigInt only to find out it's not allowed. There should be a logical workaround for this? I have an idea which is using "elementary school method" where you add each digit starting from right to left.
I made a string which I split into char array and added each digit from right to left(GetUpperBound-i). But it doesn't seem to work.
My Code:
string s, s2;
char[] c_arr, c_arr2;
int i, erg;
s = "1234";
s2 = "5678";
c_arr = s.ToCharArray();
c_arr2 = s2.ToCharArray();
for (i = 0; i <= c_arr.GetUpperBound(0); i++)
{
erg = c_arr[c_arr.GetUpperBound(0)-i]+c_arr2[c_arr2.GetUpperBound(0)-i];
Console.Write(erg);
}
Console.ReadKey();

There are a few things wrong with your code for the 'elementary school method'. You don't account for carry, you're adding up ascii values rather than actual values between 0-9, and you're outputting the results in the wrong order.
The code below, whilst not very elegant, does produce the correct results:
var s1 = "12345";
var s2 = "5678";
var carry = false;
var result = String.Empty;
if(s1.Length != s2.Length)
{
var diff = Math.Abs(s1.Length - s2.Length);
if(s1.Length < s2.Length)
{
s1 = String.Join("", Enumerable.Repeat("0", diff)) + s1;
}
else
{
s2 = String.Join("", Enumerable.Repeat("0", diff)) + s2;
}
}
for(int i = s1.Length-1;i >= 0; i--)
{
var augend = Convert.ToInt32(s1.Substring(i,1));
var addend = Convert.ToInt32(s2.Substring(i,1));
var sum = augend + addend;
sum += (carry ? 1 : 0);
carry = false;
if(sum > 9)
{
carry = true;
sum -= 10;
}
result = sum.ToString() + result;
}
if(carry)
{
result = "1" + result;
}
Console.WriteLine(result);

The following program can be used to add two large numbers, I have used string builder to store the result. You can add numbers containing digits upto '2,147,483,647'.
Using System;
using System.Text;
using System.Linq;
public class Test
{
public static void Main()
{
string term1="15245142151235123512352362362352351236";
string term2="1522135123612646436143613461344";
StringBuilder sum=new StringBuilder();
int n1=term1.Length;
int n2=term2.Length;
int carry=0;
int n=(n1>n2)?n1:n2;
if(n1>n2)
term2=term2.PadLeft(n1,'0');
else
term1=term1.PadLeft(n2,'0');
for(int i=n-1;i>=0;i--)
{
int value=(carry+term1[i]-48+term2[i]-48)%10;
sum.Append(value);
carry=(carry+term1[i]-48+term2[i]-48)/10;
}
char[] c=sum.ToString().ToCharArray();
Array.Reverse(c);
Console.WriteLine(c);
}
}

string Add(string s1, string s2)
{
bool carry = false;
string result = string.Empty;
if(s1[0] != '-' && s2[0] != '-')
{
if (s1.Length < s2.Length)
s1 = s1.PadLeft(s2.Length, '0');
if(s2.Length < s1.Length)
s2 = s2.PadLeft(s1.Length, '0');
for(int i = s1.Length-1; i >= 0; i--)
{
var augend = Convert.ToInt64(s1.Substring(i,1));
var addend = Convert.ToInt64(s2.Substring(i,1));
var sum = augend + addend;
sum += (carry ? 1 : 0);
carry = false;
if(sum > 9)
{
carry = true;
sum -= 10;
}
result = sum.ToString() + result;
}
if(carry)
{
result = "1" + result;
}
}
else if(s1[0] == '-' || s2[0] == '-')
{
long sum = 0;
if(s2[0] == '-')
{
//Removing negative sign
char[] MyChar = {'-'};
string NewString = s2.TrimStart(MyChar);
s2 = NewString;
if(s2.Length < s1.Length)
s2 = s2.PadLeft(s1.Length, '0');
for (int i = s1.Length - 1; i >= 0; i--)
{
var augend = Convert.ToInt64(s1.Substring(i,1));
var addend = Convert.ToInt64(s2.Substring(i,1));
if(augend >= addend)
{
sum = augend - addend;
}
else
{
int temp = i - 1;
long numberNext = Convert.ToInt64(s1.Substring(temp,1));
//if number before is 0
while(numberNext == 0)
{
temp--;
numberNext = Convert.ToInt64(s1.Substring(temp,1));
}
//taking one from the neighbor number
int a = int.Parse(s1[temp].ToString());
a--;
StringBuilder tempString = new StringBuilder(s1);
string aString = a.ToString();
tempString[temp] = Convert.ToChar(aString);
s1 = tempString.ToString();
while(temp < i)
{
temp++;
StringBuilder copyS1 = new StringBuilder(s1);
string nine = "9";
tempString[temp] = Convert.ToChar(nine);
s1 = tempString.ToString();
}
augend += 10;
sum = augend - addend;
}
result = sum.ToString() + result;
}
//Removing the zero infront of the answer
char[] zeroChar = {'0'};
string tempResult = result.TrimStart(zeroChar);
result = tempResult;
}
}
return result;
}
string Multiply(string s1, string s2)
{
string result = string.Empty;
//For multipication
bool Negative = false;
if(s1[0] == '-' && s2[0] == '-')
Negative = false;
else if(s1[0] == '-' || s2[0] == '-')
Negative = true;
char[] minusChar = {'-'};
string NewString;
NewString = s2.TrimStart(minusChar);
s2 = NewString;
NewString = s1.TrimStart(minusChar);
s1 = NewString;
List<string> resultList = new List<string>();
for(int i = s2.Length - 1; i >= 0; i--)
{
string multiplycation = string.Empty;
for (int j = s1.Length - 1; j >= 0; j--)
{
var augend = Convert.ToInt64(s1.Substring(j,1));
var addend = Convert.ToInt64(s2.Substring(i,1));
long multiply = augend * addend;
// print(multiply);
multiplycation = multiply.ToString() + multiplycation;
}
//Adding zero at the end of the multiplication
for (int k = s2.Length - 1 - i; k > 0; k--)
{
multiplycation += "0";
}
resultList.Add(multiplycation);
}
for (int i = 1; i < resultList.Count; i++)
{
resultList[0] = Add(resultList[0],resultList[i]);
}
//Finally assigning if negative negative sign in front of the number
if(Negative)
result = resultList[0].Insert(0,"-");
else
result = resultList[0];
return result;
}
string Divide(string dividend, string divisor)
{
string result = string.Empty;
int remainder = 0;
int intNumberstoGet = divisor.Length;
int currentInt = 0;
int dividing = int.Parse(dividend.Substring(currentInt,intNumberstoGet));
int intDivisor = int.Parse(divisor);
while(currentInt < dividend.Length)
{
if(dividing == 0)
{
currentInt++;
result += "0";
}
else
{
while(dividing < intDivisor)
{
intNumberstoGet++;
dividing = int.Parse(dividend.Substring(currentInt,intNumberstoGet));
}
if (dividing > 0)
{
remainder = dividing % intDivisor;
result += ((dividing - remainder) / intDivisor).ToString();
intNumberstoGet = 1;
if(currentInt < dividend.Length - 2)
currentInt += 2;
else
currentInt++;
if(currentInt != dividend.Length)
{
dividing = int.Parse(dividend.Substring(currentInt,intNumberstoGet));
remainder *= 10;
dividing += remainder;
}
}
}
}
return result;
}

Here you go. Another example. It's 10 to 30 times faster than the accepted answer.
static string AddNumStr(string v1, string v2)
{
var v1Len = v1.Length;
var v2Len = v2.Length;
var count = Math.Max(v1Len, v2Len);
var answ = new char[count + 1];
while (count >= 0) answ[count--] = (char)((v1Len > 0 ? v1[--v1Len] & 0xF:0) + (v2Len>0 ? v2[--v2Len]&0xF : 0));
for (var i = answ.Length - 1; i >= 0; i--)
{
if (answ[i] > 9)
{
answ[i - 1]++;
answ[i] -= (char)10;
}
answ[i] = (char)(answ[i] | 48);
}
return new string(answ).TrimStart('0');
}

Below SO question has some interesting approaches. Though the answer is in Java, but you will surely get to know what needs to be done.
How to handle very large numbers in Java without using java.math.BigInteger

public static int[] addTwoNumbers(string s1, string s2)
{
char[] num1 = s1.ToCharArray();
char[] num2 = s2.ToCharArray();
int sum = 0;
int carry = 0;
int size = (s1.Length > s2.Length) ? s1.Length + 1 : s2.Length + 1;
int[] result = new int[size];
int index = size - 1;
int num1index = num1.Length - 1;
int num2index = num2.Length - 1;
while (true)
{
if (num1index >= 0 && num2index >= 0)
{
sum = (num1[num1index]-'0') + (num2[num2index]-'0') + carry;
}
else if(num1index< 0 && num2index >= 0)
{
sum = (num2[num2index]-'0') + carry;
}
else if (num1index >= 0 && num2index < 0)
{
sum = (num1[num1index]-'0') + carry;
}
else { break; }
carry = sum /10;
result[index] = sum % 10;
index--;
num1index--;
num2index--;
}
if(carry>0)
{
result[index] = carry;
}
return result;
}

C# printing and skipping a certain number of characters

Ok, here's the problem that I have: using C# I want to format a string by printing out a certain number of characters, then skipping a certain number of characters and then again print, skip.
For example: I want to print 3 characters by skipping the next 2.
So this:
ABCDEFGHIJKL
would become this:
ABCFGHKL
I have only made that it could skip every 2,3,4 and so on characters and I couldn't think of how to approach this further.
Here is so far what I have
string text;
int print = 3;
int skip = 2;
StreamReader file = new StreamReader(#"c:\test.txt");
while ((text = file.Readtext()) != null)
{
string[] stringArray = new string[text.Length];
char ch;
for (int i = 0; i < text.Length; i++)
{
ch = text[i];
stringArray[i] = ch.ToString();
}
for (int i = 0; i < stringArray.Length; i+=skip)
{
Console.Write(stringArray[i]);
}
}
Thanks.
Thank you guys for various great solutions, I really appreciate your help! Thanks!

int take = 3;
int skip = 2;
string s = "ABCDEFGHIJKL";
var newstr = String.Join("", s.Where((c,i) => i % (skip + take) < take));
EDIT
Here are my test results....
int take = 3;
int skip = 2;
string s = String.Join("",Enumerable.Repeat("0123456789", 200));
var t1 = Measure(10000, () => { var newstr = String.Join("", s.Where((c, i) => i % (skip + take) < take)); });
var t2 = Measure(10000, () => { var newstr = new string(s.Where((c, i) => i % (skip + take) < take).ToArray()); });
var t3 = Measure(10000, () => { var newstr = GetString(s, take, skip); });
long Measure(int n,Action action)
{
action(); //JIT???
var sw = Stopwatch.StartNew();
for (int i = 0; i < n; i++)
{
action();
}
return sw.ElapsedMilliseconds;
}
OUTPUT:
1665 ms. (String.Join)
1154 ms. (new string())
7457 ms. (Sayse's GetString)
EDIT 2
Modifying Sayse's answer as below gives the fastest result among the codes i tested. (311 ms)
public string GetString(string s, int substringLen, int skipCount)
{
StringBuilder newString = new StringBuilder(s.Length);
for (int i = 0; i < s.Length; i += skipCount)
{
for (int j = 0; j < substringLen && i < s.Length; j++)
{
newString.Append(s[i++]);
}
}
return newString.ToString();
}

I like I4V's answer more but heres one way to achieve this
public string GetString(string s, int substringLen, int skipCount)
{
string newString = "";
for (int i = 0; i < s.Length; i += skipCount)
{
for (int j = 0; j < substringLen && i < s.Length; j++)
{
newString += s[i++];
}
}
return newString;
}
Edit Benchmark stated my way was faster
var newStr2 = new Program().GetString(a, take, skip);
var newstr = String.Join("", a.Where((c, i) => i % (skip + take) < take));
sw.Start();
for (int i = 0; i < 1000000; i++)
{
newStr2 = new Program().GetString(a, take, skip);
}
sw.Stop();
Console.WriteLine("my way: " + sw.Elapsed.ToString());
sw.Reset();
sw.Start();
for (int i = 0; i < 1000000; i++)
{
newstr = String.Join("", a.Where((c, iv) => iv % (skip + take) < take));
}
sw.Stop();
Console.WriteLine("I4V way: " + sw.Elapsed.ToString());
Output
my way: 00:00:00.7634927
I4V way: 00:00:01.0183307

int print = 3;
int skip = 2;
Boolean isPrintState = true;
int statePosition = 0;
StringBuilder Sb = new StringBuilder();
using (TextReader reader = new StreamReader(#"c:\test.txt")) {
while (true) {
int Ch = reader.Read();
if (Ch < 0)
break;
statePosition += 1;
if ((isPrintState && (statePosition > print)) || (!isPrintState && (statePosition > skip))) {
statePosition = 1;
isPrintState = !isPrintState;
}
if (isPrintState)
Sb.Append((Char) Ch);
}
}
Console.Write(Sb.ToString());

Amidst so many good looking answer, mine might not be so sophisticated but I thought I would post it anyways. Simple logic.
var take = 3;
var skip = 2;
StringBuilder source = new StringBuilder("ABCDEFGHIJKL");
StringBuilder result = new StringBuilder();
while (source.Length > 0)
{
if (source.Length >= take)
{
result.Append(source.ToString().Substring(0, take));
}
else
{
result.Append(source.ToString());
}
if (source.Length > skip + take)
{
source.Remove(0, skip + take);
}
else
source.Clear();
}

This how to do that.
I think this may be more clear if you are not familiar with Lambda expression
int print = 3;
int skip = 2;
string str = "ABCDEFGHILKL";
StringBuilder stringBuilder = new StringBuilder();
string res = String.Empty;
int i = 0;
while (i < str.Length)
{
stringBuilder.Append(str.Substring(i, Math.Min(print, str.Length - i)));
i += print + skip;
}
Console.WriteLine(stringBuilder.ToString());

In C# arrays, how not to create duplicated random numbers?

I'm a beginner in C#, trying to make a lottery form applicaton.
There are types, first when you have 5 tips ( otos bool ) and 5 tips ( hatos bool ).
And there are many types of how many numbers will be raffled (tiz, harminc, kilencven, negyvenot).
I tried to scan the numbers after the raffle with Array.Equals with this code:
for (int i = 0; i <= 4; i++)
{
for (int y = 0; y <= 4; y++)
{
if (Array.Equals(lottoszamok[i], lottoszamok[y]))
lottoszamok[i] = r.Next (1, ?);
}
}
but at this the number will be scanned with itself too, so it will be always equal.
here is my code by the way:
if (otos == true)
{
for (int i = 0; i <= 5; i++)
{
if (tiz == true)
{
lottoszamok[i] = r.Next(1, 10);
}
else if (harminc == true)
{
lottoszamok[i] = r.Next(1, 30);
}
else if (kilencven == true)
{
lottoszamok[i] = r.Next(1, 90);
}
else if (negyvenot == true)
{
lottoszamok[i] = r.Next(1, 45);
}
else if (egyeni == true)
{
lottoszamok[i] = r.Next(1, (egyeniertek + 1));
}
}
}
if (hatos == true)
{
for (int i = 0; i <= 6; i++)
{
if (tiz == true)
{
lottoszamok[i] = r.Next(1, 10);
}
else if (harminc == true)
{
lottoszamok[i] = r.Next(1, 30);
}
else if (kilencven == true)
{
lottoszamok[i] = r.Next(1, 90);
}
else if (negyvenot == true)
{
lottoszamok[i] = r.Next(1, 45);
}
else if (egyeni == true)
{
lottoszamok[i] = r.Next(1, (egyeniertek + 1));
}
}
}

If you're trying to pick numbers from a range 1..n without repetitions, you need to "shuffle" the numbers out:
int[] allPossibleNumbers = Enumerable.Range(1, maxNumber).ToArray();
int[] picked = new int[numberToPick];
for (int i = 0; i < numberToPick; i++)
{
int index = r.Next(i, maxNumber);
picked[i] = allPossibleNumbers[index];
allPossibleNumbers[index] = allPossibleNumbers[i];
}
where numberToPick is 5 if otos or 6 if hatos, and maxNumber depends on tiz, harminc, kilencven, negyvenot, egyeni and egyeniertek.
If your maxNumber is huge and you only want to pick a few numbers, the following doesn't require the whole range to be in memory at once:
Dictionary<int, int> outOfPlace = new Dictionary<int,int>();
int[] picked = new int[numberToPick];
for (int i = 0; i < numberToPick; i++)
{
int shuffleOut = outOfPlace.ContainsKey(i) ? outOfPlace[i] : i;
int index = r.Next(i, maxNumber);
picked[i] = 1 + (outOfPlace.ContainsKey(index) ? outOfPlace[index] : index);
outOfPlace[index] = shuffleOut;
outOfPlace.Remove(i);
}

Try this one!
if (i!=y && Array.Equals(lottoszamok[i], lottoszamok[y]))

I made it this way, if you want you could put swapping like method.
static void SwapInts(int[] array, int position1, int position2)
{
// Swaps elements in an array.
int temp = array[position1]; // Copy the first position's element
array[position1] = array[position2]; // Assign to the second element
array[position2] = temp; // Assign to the first element
}
static void Main()
{
Random rng = new Random();
int n = int.Parse(Console.ReadLine());
int[] intarray = new int[n];
for (int i = 0; i < n; i++)
{
// Initialize array
intarray[i] = i + 1;
}
// Exchange resultArray[i] with random element in resultArray[i..n-1]
for (int i = 0; i < n; i++)
{
int positionSwapElement1 = i + rng.Next(0, n - i);
SwapInts(intarray, i, positionSwapElement1);
}
for (int i = 0; i < n; i++)
{
Console.Write(intarray[i] + " ");
}
}
}

I spend many time to get this, but i believe i can do it, now it's done, By the Easier way in the word, this kill every think about Random not duplicate,very simply code without any philosophy or difficulty of Developers made ... (welcome to my work) that (BEST OF THE BEST):
Numbers between (1-10) without any duplicate, 1- MY WORK in C#
private void TenNumbersRandomly()
{
int[] a = new int[10];
Random r = new Random();
int x;
for (int i = 0; i < 10; i++)
{
x= r.Next(1, 11);
for (int j = 0; j <= i ; j++)
{
while (a[j] == x)
{
x = r.Next(1, 11);
j = 0;
}
}
a[i] = x;
tb1.Text += a[i]+"\n";
}
}
2- in VB some Different i also have it :
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim x As Integer, i As Integer, j As Integer
x = Int(Rnd() * 10) + 1
Label1.Text = ""
Dim a(9) As Integer
For i = 0 To 9
x = Int(Rnd() * 10) + 1
For j = 0 To i
While (a(j) = x)
x = Int(Rnd() * 10) + 1
j = 0
End While
Next j
a(i) = x
Label1.Text += a(i).ToString() + " "
Next i