记录详情 - JMYSOJ (jmfes.com) 包AC的

```#include
#include <bits/stdc++.h>
using namespace std;
int n, b;
int a[30];
int minn = 1e9;

int per[15];
//u表示处理到的数字下标，sum表示已经选取的数字和
void dfs (int u, int sum){
if(sum >= b && sum <= minn){
minn = sum;
return;
}
for(int i = u; i <= n; i ++){
dfs(i + 1, sum + a[i]);
}
}

int main(){
freopen("shelf.in", "r", stdin);
freopen("shelf.out", "w", stdout);
cin >> n >> b;
for(int i = 1; i <= n; i ++){
cin >> a[i];
}
dfs(1, 0);
cout << minn - b;
return 0;
}