要求 给出一个正整数n,寻找最少的完全平方数,使他们的和为n 示例 n = 12 12 = 4 + 4 + 4 输出:3 边界 是否可能无解 思路 贪心:12=9+1+1+1,无法得到最优解 图论:从n到0,每个数字表示一个节点,如果两个数字x到y相差一个完全平方数,则连接一条边 问题转化为无权图中从n到0的最短路径    实现 队列中每个元素是一个pair对,保存具体数字和经历了几段路径走到这个数字 1 class Solution { 2 public: 3 int numSquares(i…

原文地址 https://www.jianshu.com/p/2925f4d7511b 迫于就业的压力,不得不先放下 iOS 开发的学习,开始走上漫漫刷题路. 今天我想聊聊 LeetCode 上的第279题-Perfect Squares,花了挺长时间的,试了很多方法,作为一个算法新手,个人感觉这题很好,对我的水平提升很有帮助.我在这里和大家分享一下我的想法.下面是题目: Given a positive integer n, find the least number of perfect s…

Given a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, ...) which sum to n. Example 1: Input: n = 12 Output: 3 Explanation: 12 = 4 + 4 + 4. Example 2: Input: n = 13 Output: 2 Explanation: 13 = 4 + 9.---…

Given a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, ...) which sum to n. Example 1: Input: n = 12 Output: 3 Explanation: 12 = 4 + 4 + 4. Example 2: Input: n = 13 Output: 2 Explanation: 13 = 4 + 9. Cr…

Given a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, ...) which sum to n. For example, given n = 12, return 3 because 12 = 4 + 4 + 4; given n = 13, return 2 because 13 = 4 + 9. 代码如下: public class Solu…

https://leetcode.com/problems/perfect-squares/ Given a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, ...) which sum to n. For example, given n = 12, return 3 because 12 = 4 + 4 + 4; given n = 13, retur…

Given a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, ...) which sum to n. Example 1: Input: n = 12 Output: 3 Explanation: 12 = 4 + 4 + 4. Example 2: Input: n = 13 Output: 2 Explanation: 13 = 4 + 9. dp…

原题链接 题意: 给一个非整数,算出其最少可以由几个完全平方数组成(1,4,9,16……) 思路: 可以得到一个状态转移方程  dp[i] = min(dp[i], dp[i - j * j] + ); 代码如下: Runtime: 60 ms, faster than 69.83% 有点慢 class Solution { public: int numSquares(int n) { ]; ; i <= n; i++) { dp[i] = i; ; j * j <= i; j++) { d…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 四平方和定理 动态规划 日期 题目地址:https://leetcode.com/problems/perfect-squares/ 题目描述 Given a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, -…

给定正整数 n,找到若干个完全平方数(比如 1, 4, 9, 16, ...) 使得他们的和等于 n.你需要让平方数的个数最少.比如 n = 12,返回 3 ,因为 12 = 4 + 4 + 4 : 给定 n = 13,返回 2 ,因为 13 = 4 + 9. 详见:https://leetcode.com/problems/perfect-squares/description/ Java实现: 方法一:递归实现 class Solution { public int numSquares(i…