原题链接在这里:https://leetcode.com/problems/sum-of-square-numbers/description/
题目:
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
题解:
在[0, (int)Math.sqrt(c)]区间内用two points夹比.
Time Complexity: O(sqrt(c)). Space: O(1).
AC Java:
1 class Solution { 2 public boolean judgeSquareSum(int c) { 3 if(c < 0){ 4 return false; 5 } 6 7 int l = 0; 8 int r = (int)Math.sqrt(c); 9 while(l<=r){ 10 int cur = l*l + r*r; 11 if(cur == c){ 12 return true; 13 }else if(cur < c){ 14 l++; 15 }else if(cur > c){ 16 r--; 17 } 18 } 19 return false; 20 } 21 }
时间: 2024-10-11 12:00:01