Integer Complemet of a Number or Once Complemet of a Integer

This was a program given to me in an interview unfortunately I was not able to complete it in very short time hence I am writing this code here so that this may help any one ;-)

C++ Source :

#include<iostream>

#include<conio.h>

#include<string>

using namespace std;

int GetIntegerComplement(int nInputNum)

{

int nRemider = 0, nCompRem = 0, nSum = 0, nCompSum=0, nTempNum;

int nPos=1;

string strComp="";

char ChArray[2];

size_t Size = 1;

nTempNum = nInputNum;

do

{

nRemider = nTempNum % 2;

if (nRemider == 0)

{

nCompRem = 1;

}

else

{

nCompRem = 0;

}

nSum = nSum + (nPos*nRemider);

nCompSum = nCompSum + (nPos*nCompRem);

_itoa(nCompRem,ChArray,10);

strComp = strComp + string(ChArray);

nTempNum = nTempNum / 2;

nPos = nPos * 10;

} while (nTempNum>0);

cout << "\n The Binary equivalent of " << nInputNum << " is " << nSum;

int nIntComp = 0;

nPos = 0;

nRemider = 0;

while (nCompSum > 0)

{

nRemider = nCompSum % 10;

nIntComp = nIntComp + pow(2,nPos)*nRemider;

nCompSum = nCompSum / 10;

nPos++;

}

reverse(strComp.begin(),strComp.end());

cout << "\n The complement Binary equivalent" << " is " << strComp;

return nIntComp;

}

void main()

{

int nNumber;

cout << "\n Enter a number to Convert to Binary";

cin >> nNumber;

cout << "\n The Integer complement of " << nNumber << " is " << GetIntegerComplement(nNumber);

_getch();

}

C# Source:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace DecimalOnceComplement

{

    class Program

    {

        static int GetIntegerComplement(int nInputNum)

        {

           int nRemider = 0, nCompRem = 0, nSum = 0, nCompSum=0, nTempNum;

           int nPos=1;

           string strComp="";

           nTempNum = nInputNum;

        do

           {

           nRemider = nTempNum % 2;

           if (nRemider == 0)

           {

           nCompRem = 1;

           }

           else

           {

           nCompRem = 0;

           }

               nSum = nSum + (nPos*nRemider);

               nCompSum = nCompSum + (nPos*nCompRem);

                        strComp = strComp + nCompRem.ToString();

               nTempNum = nTempNum / 2;

               nPos = nPos * 10;

          } while (nTempNum>0);

           Console.WriteLine(" The Binary equivalent of {0} is {1}",nInputNum,nSum);

           int nIntComp = 0;

           nPos = 0;

           nRemider = 0;

          while (nCompSum > 0)

          {

           nRemider = nCompSum % 10;

           nIntComp = nIntComp + (int)(Math.Pow(2,nPos))*nRemider;

           nCompSum = nCompSum / 10;

           nPos++;

       }

               strComp = ReverseString(strComp);

        Console.WriteLine( " The complement Binary equivalent is {0}",strComp);

       return nIntComp;

       

        }

        public static string ReverseString(string s)

        {

            char[] arr = s.ToCharArray();

            Array.Reverse(arr);

            return new string(arr);

        }

        static void Main(string[] args)

        {

            int nNumber;

            string strInput;

            Console.WriteLine(" Enter a number to Convert to Binary:");

            strInput = Console.ReadLine();

            nNumber = Convert.ToInt32(strInput);

            Console.WriteLine(" The Integer complement of {0} is {1}" ,nNumber,GetIntegerComplement(nNumber));

            Console.ReadLine();

        }

    }

}

Out Put :