自学一下bitset就可以看懂了

#include <bits/stdc++.h>
using namespace std;
#define accelerate ios::sync_with_stdio(false),cin.tie(0);
#define int long long
#define PII pair<int,int>
#define mod 1000000007
#define ufor(i,st,en) for(int i=st;i<=en;i++)
#define dfor(i,en,st) for(inNt i=en;i>=st;i--)
const int N = 1e6 + 10;
const int INF = 1e15;
int n, m, k, x, y, xx, yy, T, q, S;
bitset<N>s;
signed main(){
	accelerate;
	cin>>n;
	cin>>x;
	s[x]=1;
	ufor(i,2,n){
		cin>>x;
		s|=s<<x;
		s[x]=1;
	}
	cout<<s.count();
	return 0;
}