Check if two integers are equal without using any comparison operators

Problem statement: Given two integers, you need to check if they are equal or not, without using any comparison operators.

Solution: An optimized solution can be given using bitwise XOR operator. The bitwise XOR of two numbers is 0 only if each corresponding bit in the two numbers is same, i.e. the numbers are equal.

?

1 2 3 4

int isUnequal(int a, int b) {     return a ^ b;    // Returns zero if the numbers are equal, else a non-zero value }

Since (a ^ b) might be any integer value, we can strictly restrict the return value to either 0 or 1 like this:

?

1 2 3 4

int isUnequal(int a, int b) {     return !!(a ^ b);    // Returns zero if the numbers are equal, else returns one }

Another simple solution could be using the minus operator:

?

1 2 3 4

int isUnequal(int a, int b) {     return !!(a - b);    // Returns zero if the numbers are equal, else returns one }