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
class Solution { public boolean judgeSquareSum(int c) { for(int i = 0; i<= (int)Math.sqrt(c);i++) for(int j = 0; (int)j<=Math.sqrt(c); j++){ if(i*i+j*j ==c){ System.out.println("i= "+i+" j = "+j); return true; } } return false; } }
Will work for large proportion of the test cases, but would have overflow or Time Limit Exception
class Solution { public boolean judgeSquareSum(int c) { int begin = 0; int end = (int) Math.sqrt(c); while (begin<=end){ int tmp = begin*begin + end * end; if(tmp< c){ begin++; } else if(tmp >c){ end--; } else{ return true; } } return false; } }
(Easy) Sum of Square Numbers - LeetCode
原文：https://www.cnblogs.com/codingyangmao/p/11429387.html