题解 | #兑换零钱#

完全背包模版题

import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner reader = new Scanner(System.in);
        int n = reader.nextInt();
        int aim = reader.nextInt();
        int[] arr = new int[n + 1];
        for (int i = 1; i <= n; i++) {
            arr[i] = reader.nextInt();
        }
        int[] dp = new int[aim + 1];
        // 完全背包
        Arrays.fill(dp, Integer.MAX_VALUE - 10001);
        dp[0] = 0;
        for (int i = 1; i <= aim; i++) {
            for (int j = 1; j <= n; j++) {
                if (i >= arr[j]) {
                    dp[i] = Math.min(dp[i - arr[j]] + 1, dp[i]);
                }
            }
        }
        if (dp[aim] == Integer.MAX_VALUE - 10001) 
            System.out.println(-1);
        else 
            System.out.println(dp[aim]);
    }
}