package com.fishercoder.solutions;

import java.util.Arrays;

/**
 * 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.
 */
public class _279 {

    public int numSquares(int n) {
        int result = n;
        int num = 2;
        while (num * num <= n) {
            int temp1 = n / (num * num);
            int temp2 = n % (num * num);
            result = Math.min(result, temp1 + numSquares(temp2));
            num++;
        }
        return result;
    }

    //DP solution
    public int numSquaresDP(int n) {
        int[] dp = new int[n + 1];
        Arrays.fill(dp, Integer.MAX_VALUE);
        dp[0] = 0;
        dp[1] = 1;
        for (int i = 1; i <= n; i++) {
            int min = Integer.MAX_VALUE;
            int j = 1;
            while (i - j * j >= 0) {
                min = Math.min(min, dp[i - j * j] + 1);
                j++;
            }
            dp[i] = min;
        }
        return dp[n];
    }

}

package com.fishercoder.solutions;

import java.util.Arrays;

/**
 * 279. 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.
 */
public class _279 {
    public static class Solution1 {
        public int numSquares(int n) {
            int result = n;
            int num = 2;
            while (num * num <= n) {
                int temp1 = n / (num * num);
                int temp2 = n % (num * num);
                result = Math.min(result, temp1 + numSquares(temp2));
                num++;
            }
            return result;
        }
    }

    public static class Solution2 {
        //DP solution
        public int numSquares(int n) {
            int[] dp = new int[n + 1];
            Arrays.fill(dp, Integer.MAX_VALUE);
            dp[0] = 0;
            dp[1] = 1;
            for (int i = 1; i <= n; i++) {
                int min = Integer.MAX_VALUE;
                int j = 1;
                while (i - j * j >= 0) {
                    min = Math.min(min, dp[i - j * j] + 1);
                    j++;
                }
                dp[i] = min;
            }
            return dp[n];
        }
    }

}

refactor 279