Problem:
Coin Changing Problem

Find the minimum number of coins to make change for n cents using coins of denominations d1, d2,.., dm. The coins can be used any number of times.

Input

n m
d1 d2 ... dm

Two integers n and m are given in the first line. The available denominations are given in the second line.

Output

Print the minimum number of coins in a line.

Constraints

1 ≤ n ≤ 50000

1 ≤ m ≤ 20

1 ≤ denomination ≤ 10000

The denominations are all different and contain 1.

Sample Input 1

55 4
1 5 10 50

Sample Output 1

2

Sample Input 2

15 6
1 2 7 8 12 50

Sample Output 2

2

Sample Input 3

65 6
1 2 7 8 12 50

Sample Output 3

3

Solution in JAVA (judge verdict: WA: Presentation Error)

import java.util.*;
import java.math.*;
class Main{
	public static void main(String args[]){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int m = sc.nextInt();
		int[] coins = new int[m];
		for(int i = 0; i < m; i++){
			coins[i] = sc.nextInt();
		}
		int[] times = new int[n+1];
		times[0] = 0;
		for(int j = 1; j<= n; j++){
			times[j] = Integer.MAX_VALUE;
		}
		for(int j = 1; j <= n; j++){
			for(int i = 0; i < m; i++){
				if(j - coins[i] >= 0){
					times[j] = Math.min(times[j], times[j-coins[i]]+1);
				}
			}
		}
		System.out.println(times[n] + "\n");
	}
}