题解 | 数组分组

#include<bits/stdc++.h>
using namespace std;

int n;
int n3,n5,n35;
vector<int> v;

bool dfs(int i,int sum){
	if(i==v.size()){
		return n35==sum;
	}
	return (dfs(i+1,sum+v[i])||dfs(i+1,sum-v[i]));
}

int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin>>n;
	int t;
	for(int i=1;i<=n;i++){
		cin>>t;
		if(t%5==0){
			n5+=t;
		}else if(t%3==0){
			n3+=t;
		}else{
			v.push_back(t);
		}
	}
	n35=abs(n3-n5);
	
	if(dfs(0,0)){
		cout<<"true"<<endl;
	}else{
		cout<<"false"<<endl;
	}
    return 0;
}