A 代码
35ms / 680.00KB / 292B C++14 (GCC 9) O2

#include<bits/stdc++.h>
using namespace std;
int dp[10001]={1};
int main(){
   int n,m;cin >> n >> m;
   for(int i = 1,u;i <= n;i ++)
   {
       cin>>u;
       for(int j = m;j >= u;j --)
       {
           dp[j] = dp[j] + dp[j- u];
       }
   }
   cout << dp[m];
   return 0;
}

B 代码
33ms / 604.00KB / 690B C++14 (GCC 9) O2

#include<bits/stdc++.h>
using namespace std;
int dp[10005];int arr[105];
int main(){
   int n,m;cin >> n >> m;
   for(int i = 1;i <= n;i ++) cin >> arr[i];
   dp[0] = 1;
   for(int i = 1;i <= n;i ++)
   {
   	for(int j = m;j >= arr[i];j --)
   	{
   		dp[j] = dp[j] + dp[j- arr[i]]; 
   	}
   }
   cout << dp[m];
   return 0;
}