Leetcode Perfect Squares 279

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.

题目链接

dp

class Solution {public:    int numSquares(int n) {        int dp[10000];        dp[1]=1;        for(int i=2;i<=n;i++){            int j=1;            int min_=100000000;            while(j*j<=i){                if(j*j==i) {                    min_=1;                }                min_=min(min_,dp[i-j*j]+1);                j++;            }            dp[i]=min_;        }        return dp[n];    }};