Question

Write a C program which accept two strings and print characters in second string which are not present in first string?

Example:
String 1: apple
String 2: aeroplane

output:
ron

Answer 1

I wrote a program which is giving the expected outcome.

#include<stdio.h>

int main(int argc, char *argv[])
{
   char *str1 = argv[1]; /*"apple";*/
   char *str2 = argv[2]; /*"aeroplane";*/
   int bitMask = 0;

   while (*str1 != '\0')
   {
      bitMask = bitMask | (1<< (*str1 - 'a'));
      str1++;
   }

   while (*str2 != '\0')
   {
      if (!(bitMask & (1<<(*str2 - 'a'))))
      printf("%c", *str2);
      str2++;
   }

   return(0);
}

Here, bitMask is an integer 32 bit long variable.