Write a Program to Subtract Two Numbers Without Using Subtraction (-) Operator

Logic of a Program

To subtract two numbers here we are using 2's complement. To understand the logic let's take two number 4 and 3.

First calculate the  2's Complement of 3.

Binary representation of 3 is  0011

Now 1's complement can be obtained by inverting all the bits of binary representation of 3. And by adding 1 in 1's complement we get 2's complement.

1's complement of 3 is 1100.
2's complement of 3 is 1101. ( By adding 1 in 1's complement we get 2's complement).

Let's add 4 and 2's complement of 3.

0100 + 1101 =    0001 ( This is the binary representation of 1).

Tricky Problems

Add Two Numbers Without Using Addition Operator

Write a Program to Subtract Two Numbers Without Using Subtraction (-) Operator

#include<stdio.h>

int main(){
   
    int firstnum,secondnum,result,complement;
    

    printf("Enter any two numbers ");
    scanf("%d%d",&firstnum,&secondnum);

    // Take two's complement of a number

    complement = ~secondnum +1;
    
    // Add firstnum with two's complement
    result = firstnum + complement;

    // Final result
    printf("Difference of two integers: %d",result);

    return 0;
}