1. Description

You are given coins of different denominations and a total amount of money amount. Write a function to compute the fewest number of coins that you need to make up that amount. If that amount of money cannot be made up by any combination of the coins, return -1.

Note: You may assume that you have an infinite number of each kind of coin.

2. Runtime Distribution

3. Submission Details

4. Example

coins = [1, 2, 5], amount = 11
return 3 (11 = 5 + 5 + 1)

coins = [2], amount = 3
return -1.

5. Code

import java.util.Arrays;

public class LeetCode0322 {
    public int coinChange(int[] coins, int amount) {
        if (coins == null || coins.length == 0 || amount <= 0) {
            return 0;
        }

        long[] dp = new long[amount + 1];

        Arrays.fill(dp, Integer.MAX_VALUE);

        dp[0] = 0;

        for (int i = 0; i < dp.length; i++) {
            for (int j = 0; j < coins.length; j++) {
                if ((long)i + coins[j] <= amount) {
                    dp[i + coins[j]] = Math.min(dp[i + coins[j]], dp[i] + 1);
                }
            }
        }

        return dp[amount] >= Integer.MAX_VALUE ? -1 : (int) dp[amount];
    }

    public static void main(String[] args) {
        LeetCode0322 leetcode = new LeetCode0322();
        int[] coins = new int[] { 2147483647 };
        System.out.println(leetcode.coinChange(coins, 2));
    }
}