题目描述：力扣

解题思路：

动态规划：自下而上 

具体参考：https://leetcode-cn.com/problems/coin-change/solution/322-ling-qian-dui-huan-by-leetcode-solution/ 方法三

 

public class Solution {
  public int coinChange(int[] coins, int amount) {
    int max = amount + 1;
    int[] dp = new int[amount + 1];
    Arrays.fill(dp, max);
    dp[0] = 0;
    for (int i = 1; i <= amount; i++) {
      for (int j = 0; j < coins.length; j++) {
        if (coins[j] <= i) {
          dp[i] = Math.min(dp[i], dp[i - coins[j]] + 1);
        }
      }
    }
    return dp[amount] > amount ? -1 : dp[amount];
  }
}