[leetcode]633. Sum of Square Numbers平方数之和

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

题意：

给定非负整数c，问是否存在整数a、b，使得 a² + b² = c

code

 1 class Solution {
 2      public boolean judgeSquareSum(int c) {
 3         if (c < 0) {
 4             return false;
 5         }
 6         int left = 0, right = (int)Math.sqrt(c);
 7         while (left <= right) {
 8             int cur = left * left + right * right;
 9             if (cur < c) {
10                 left++;
11             } else if (cur > c) {
12                 right--;
13             } else {
14                 return true;
15             }
16         }
17         return false;
18     }
19 }

[leetcode]633. Sum of Square Numbers平方数之和

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