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, return 2 because 13 = 4 + 9.

Solution:

public class Solution {
    public int numSquares(int n) {
        int[] ans = new int[n+1];
        int[] sq_list = new int[n+1];

        for(int i = 1; i < n+1; i++){
            ans[i] = Integer.MAX_VALUE/2;
            sq_list[i] = i*i;
            for(int square: sq_list){
                if(i < square) break;
                else ans[i] = Math.min(ans[i],ans[i - square]);
            }
            ans[i] = ans[i]+1;
        }
        return ans[n];
    }
}