0322-coin-change.java

import java.util.Arrays;

class Solution {

    public int coinChange(int[] coins, int amount) {
        if (amount < 0 || coins.length == 0 || coins == null) {
            return 0;
        }
        int[] dp = new int[amount + 1];
        Arrays.fill(dp, amount + 1);
        dp[0] = 0;

        for (int i = 1; i <= amount; i++) {
            for (int coin : coins) {
                if (i - coin >= 0) {
                    dp[i] = Math.min(dp[i], 1 + dp[i - coin]);
                }
            }
        }

        return dp[amount] != amount + 1 ? dp[amount] : -1;
    }
}