LeetCode（371） Sum of Two Integers

Posted 2022-06-22 逆風的薔薇

题目

Calculate the sum of two integers a and b, but you are not allowed to use the operator + and -.

Example:
Given a = 1 and b = 2, return 3.

分析

考察位运算，不用+ - 计算两数之和。

代码

/*
371. Sum of Two Integers
*/

#include <iostream>
#include <cstdlib>

using namespace std;

class Solution 
public:
	//递归解决
	int getSum1(int a, int b)
	
		if (a != 0 && b != 0)
		
			return getSum(a^b, (a&b) << 1);
		
		else 
			return a | b;
		//else
	

	//非递归
	int getSum(int a, int b) 
		if (a != 0 && b != 0)
		
			int sum = a;
			while (b != 0)
			
				sum = a ^ b;
				b = (a & b) << 1;

				a = sum;
			//while
			return sum;
		
		else 
			return a | b;
		//else
		
	
;

int main()

	cout << Solution().getSum(10, 11) << endl;

	system("pause");
	return 0;