Suppose we have two integers a and b. Our task is to find the sum of these two integers. One constraint is that, we cannot use any operator like + or -. So if a = 5 and b = 7, the result will be 12.
To solve this, we will follow these steps −
- For solving we will use the bitwise logical operators
- If b = 0, then return a
- otherwise, recursively use the sum function by providing an XOR b, and a AND b after left shifting the result one time
Example (Python)
Let us see the following implementation to get a better understanding −
#include <iostream>
using namespace std;
class Solution {
public:
int getSum(int a, int b) {
return b == 0?a:getSum(a^b, (unsigned int)(a&b)<<1);
}
};
main(){
Solution ob;
cout<<ob.getSum(5,7)<<endl;
}Input
a = 5 b = 7
Output
12