大法师

#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
int n,m,ans = 0;
int v[1002];
int dfs(int a , int b){
    if(b==0){
        return 1;
    }
    if(a>n || b<0)return 0;
    return dfs(a+1 , b) + dfs(a+1 , b-v[a]);
}
int main()
{
    cin>>n>>m;
    for(int i = 1; i <= n; i ++ )cin>>v[i];
    cout<<dfs(1,m)<<endl;
    return 0;
}

y总的dp

#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
int n,m,v;
int dp[10010];2

int main()
{
    cin>>n>>m;
    dp[0] = 1;
    for(int i = 1; i <= n; i ++ ){
        cin>>v;
        for(int j = m; j >= v; j -- ){
            dp[j]+=dp[j-v];
        }
    }
    cout<<dp[m]<<endl;
    return 0;
}