Question

I am trying to write a c++ program that will add two binary numbers that are entered into the command line. I cannot get the program to send anything to stdout. code attached.

int main(int argc, char *argv[])
//           IN       IN
{
   char partialSum[MAX_DIGITS + 1]; //partial sum of the binary numbers
   char sum[MAX_DIGITS + 1];       //sum of the binary numbers
   bool noError;       //no error flag
  
   //Exit if insufficient arguments passed to function
   if (argc < 3)
   {
       cout << "Insufficient arguments passed" << endl;
       return 1;
   }
  
   //Add the first two binary numbers on the command line.
   noError = Badd(argv[1], argv[2], sum);
  
   //Add additional binary numbers to the partial sum
   for (int counter = 3; noError && counter < argc; counter++)
   {
       strcpy(partialSum, sum);
       noError = Badd(partialSum, argv[counter], sum);
   }
  
   //Print the answer to standard output
   if (noError)
   {
       for (int counter = 0; counter < strlen(sum); counter++)
       {
           cout << sum[counter];
       }
       cout << endl;
   }
   else
       cout << 'E' << endl;
      
   return 0;
}// end main function

bool Badd(const char augend[], const char addend[], char sum[])
//           IN                   IN                   OUT
//PRE: augend and addend are strings representing valid binary numbers
//POST: sum is a string representing augend + addend
//returns true if addition is successful and false if otherwise
{
   char carry = '0'; //Carry after addition
   int lsl; //Longer string length
   int augl = strlen(augend) - 1; //length of augend string
   int addl = strlen(addend) - 1; //length of addend string
   int augDigit; //element of augend string
   int addDigit; //element of addend string
  
   if (strlen(augend) > strlen(addend))
   {
       lsl = strlen(augend);
   }
  
   else if(strlen(augend) < strlen(addend))
   {
       lsl = strlen(addend);
   }
  
   else if (strlen(augend) == strlen(addend))
   {
       lsl = strlen(augend);
   }
  
   sum[lsl] = '\0';
   for (int counter = lsl - 1; counter < 0; counter--)
   {
       augDigit = (augl < 0) ? '0' : augend[augl--];
       addDigit = (addl < 0) ? '0' : addend[addl--];
      
       if (carry == '0' && augend[augDigit] == '0' && addend[addDigit] == '0')
       {
           sum[counter] = '0';
           carry = '0';
       }
      
       else if(carry == '1' && augend[augDigit] == '0' && addend[addDigit] == '0')
       {
           sum[counter] = '1';
           carry = '0';
       }
      
       else if(carry == '0' && augend[augDigit] == '1' && addend[addDigit] == '0')
       {
           sum[counter] = '1';
           carry = '0';
       }
      
       else if(carry == '0' && augend[augDigit] == '0' && addend[addDigit] == '1')
       {
           sum[counter] = '1';
           carry = '0';
       }
       else if(carry == '1' && augend[augDigit] == '1' && addend[addDigit] == '0')
       {
           sum[counter] = '0';
           carry = '1';
       }
      
       else if(carry == '0' && augend[augDigit] == '1' && addend[addDigit] == '1')
       {
           sum[counter] = '0';
           carry = '1';
       }
      
       else if(carry == '1' && augend[augDigit] == '0' && addend[addDigit] == '1')
       {
           sum[counter] = '0';
           carry = '1';
       }
      
       else if(carry == '1' && augend[augDigit] == '1' && addend[addDigit] == '1')
       {
           sum[counter] = '1';
           carry = '1';
       }
   }
  
   if (strlen(sum) > MAX_DIGITS)
       return false;
  
   else
       return true;
} //end of Badd function

Answer 1

This is the updated code that prints the output, just made use of string class of c++

#include<bits/stdc++.h>
using namespace std;

#define MAX_DIGITS 32
string ans;
string addBinary(string a, string b)
{
string result = ""; // Initialize result
int s = 0; // Initialize digit sum
  
// Travers both strings starting from last
// characters
int i = a.size() - 1, j = b.size() - 1;
while (i >= 0 || j >= 0 || s == 1)
{
// Comput sum of last digits and carry
s += ((i >= 0)? a[i] - '0': 0);
s += ((j >= 0)? b[j] - '0': 0);
  
// If current digit sum is 1 or 3, add 1 to result
result = char(s % 2 + '0') + result;
  
// Compute carry
s /= 2;
  
// Move to next digits
i--; j--;
}
return result;
}
bool Badd(const char augend[], const char addend[])
// IN IN OUT
//PRE: augend and addend are strings representing valid binary numbers
//POST: sum is a string representing augend + addend
//returns true if addition is successful and false if otherwise
{
string a = "",b="",c;
for(int i=0;i<strlen(augend);i++)
    a = a + augend[i];
for(int i=0;i<strlen(addend);i++)
    b = b + addend[i];

ans = addBinary(a,b);
return true;

} //end of Badd function
int main(int argc, char *argv[])
// IN IN
{
char partialSum[MAX_DIGITS + 1]; //partial sum of the binary numbers
char sum[MAX_DIGITS + 1]; //sum of the binary numbers
bool noError; //no error flag

//Exit if insufficient arguments passed to function
if (argc < 3)
{
cout << "Insufficient arguments passed" << endl;
return 1;
}
  
//Add the first two binary numbers on the command line.
noError = Badd(argv[1], argv[2]);
  

  
//Print the answer to standard output
if (noError)
{
cout << ans ;
cout << endl;
}
else
cout << 'E' << endl;
  
return 0;
}// end main function


Thank you, please upvote.