题目描述:
LeetCode 633. Sum of Square Numbers
Given a non-negative integer c, your task is to decide whether there’re two integers a and b such that a2 + b2 = c.
Example 1:
Input: 5
Output: True
Explanation: 1 * 1 + 2 * 2 = 5
Example 2:
Input: 3
Output: False
题目大意:
给定非负整数c,判断是否存在两个整数a和b,满足a^2 + b^2 = c
解题思路:
在范围[0, int(sqrt(c))]内枚举a,判断c - a^2是否为完全平方数
C++代码:
class Solution {
public:
bool judgeSquareSum(int c) {
int temp=0;
for(int i=0;i<=sqrt(c);++i){
temp = c-i*i;
if(int(sqrt(temp))*int(sqrt(temp)) == temp){
return true;
}
}
return false;
}
};
题目中,4对应true, 0对应true
原文:http://bookshadow.com/weblog/2017/07/02/leetcode-sum-of-square-numbers/