Sum of Two Integers
The sum of two integers a and b, where a and b are 32-bit signed integers, is to be calculated without using the + operator.
Constraints:
- -2^31 <= a, b <= 2^31 - 1
Examples:
Input: a = 1, b = 2
Output: 3
Explanation: The sum of 1 and 2 is 3.
Solutions
Bit Manipulation
Time: O(1)Space: O(1)
The solution uses bitwise operations to calculate the sum of two integers. The XOR operation (^) is used to calculate the sum without considering the carry, and the AND operation (&) is used to calculate the carry. The left shift operation (<<) is used to shift the carry to the left by one bit.
public int getSum(int a, int b) {
while (b != 0) {
int sum = a;
a = a ^ b;
b = (sum & b) << 1;
}
return a;
}Follow-up:
How would you calculate the product of two integers without using the * operator?
