How to compare two numbers in C without using relational operators?

Question

Say I have given two big numbers i.e. 10^8 and 10^9 what could be the best way to multiply them without facing the overflow issue.

Answer 1

try this code :

#include<bits/stdc++.h>
using namespace std;
int main()
 {
  int num1,num2,diff,absoluteofDiff;
  scanf("%d %d",&num1,&num2);
  diff=num1-num2;
  num1=abs(diff);
  num2=diff+num1;
  if (num1==0)
     printf("num1 == num2\n");
  else if(num2==0)
  printf("num1<num2\n");
  else
  printf("num1>num2\n");
  return 0;
}

Answer 2

Another solution without using '==' too and I used bitwise operator.

#include<stdio.h>
int findMax( int x, int y)
{
   int z = x - y;
   int i  = (z  >>  31)  &  0x1;
   int  max  =  x - i  *  z;
   return max;
}
int main()
{
    int a,b,max;
    scanf("%d %d",&a,&b);
    max=findMax(a,b);
    printf("%d",max);
}