[LeetCode]633. Sum of Square Numbers

https://leetcode.com/problems/sum-of-square-numbers/#/description

给一个数字c，判断是否满足a2 + b2 = c

双指针，end最大为c开根号，beg最小为0.判断当前beg和end是否满足，然后相应移动beg或者end

public class Solution {    public boolean judgeSquareSum(int c) {        int beg = 0;        int end = (int) Math.sqrt(c);        while (beg <= end) {        int target = beg * beg + end * end;        if (target > c) {        end--;        } else if (target < c) {        beg++;        } else {        return true;        }        }        return false;    }}