sicily 2014

全排

#include <iostream>
using namespace std;
int n, c, count;
int coins[300];
void _find(int sum, int cur) {
	sum -= coins[cur];
	for(int i = 0; (sum = sum + coins[cur]) <= n; i++) {
		if(sum == n) {
			count++;
			return;
		}
		if(cur < c - 1) _find(sum, cur + 1);
	}
}
int main() {
	while(cin >> n >> c) {
		for(int i = 0; i < c; i++) cin >> coins[i];
		count = 0;
		_find(0, 0);
		cout << count << endl;
	}
	return 0;
}