LeetCode-in-Java
371. Sum of Two Integers
Medium
Given two integers a and b, return the sum of the two integers without using the operators + and -.
Example 1:
Input: a = 1, b = 2
Output: 3
Example 2:
Input: a = 2, b = 3
Output: 5
Constraints:
-1000 <= a, b <= 1000
Solution
public class Solution {
public int getSum(int a, int b) {
int ans = 0;
int memo = 0;
int exp = 0;
int count = 0;
while (count < 32) {
int val1 = a & 1;
int val2 = b & 1;
int val = sum(val1, val2, memo);
memo = val >> 1;
val = val & 1;
a = a >> 1;
b = b >> 1;
ans = ans | (val << exp);
exp = plusOne(exp);
count = plusOne(count);
}
return ans;
}
private int sum(int val1, int val2, int val3) {
int count = 0;
if (val1 == 1) {
count = plusOne(count);
}
if (val2 == 1) {
count = plusOne(count);
}
if (val3 == 1) {
count = plusOne(count);
}
return count;
}
private int plusOne(int val) {
return (-(~val));
}
}