279. Perfect Squares

class Solution {public:    int numSquares(int n) {        if(n<=0)            return 0;        vector<int> dp(n+1,INT_MAX);        dp[0]=0;        for(int i=1;i<=n;i++)        {            int temp=dp[i];            for(int j=1;j*j<=i;j++)            {                temp=min(temp,dp[i-j*j]+1);            }            dp[i]=temp;        }        return dp[n];    }};