Tricky addition

Write a function to add to integers without using mathematical operators (+, -, *, /, ^).

Solution :

We use the logic used in digital circuits where sum = A XOR B and carry = A AND B. We simply add the carry again after shifting it 1 left till it become zero.

Complexity :

• Time : O(1)
• Space : O(1)

Code :

int add(int a, int b){

int carry = 0;
while(b){

carry = a & b;
a = a ^ b;
b = carry << 1;

}
return a;

}