leetcode279

public class Solution
    {
        public int NumSquares(int n)
        {
            var list = new List<int>();
            list.Add(0);
            for (int i = 1; i <= n; i++)
            {
                list.Add(i);//每一个数字，初始化为全部由1构成
            }
            for (int i = 2; i <= n; i++)
            {
                for (int j = 1; j * j <= i; j++)
                {
                    var x = list[i];//当前值的构成数量
                    var s = i - j * j;//余数的下标
                    var t = list[s];//余数值的构成数量
                    var y = t + 1;//余值构成数量+1个完美平方数

                    list[i] = Math.Min(x, y);
                }
            }
            return list[n];
        }
    }