#include <iostream>
#include <vector>
using namespace std;
 
vector<vector<int>> out;
void f(int N,int L,const vector<int>&prefix){
  auto arr=prefix;
  for(auto i=arr.empty()?0:arr.back()+1;i<N;i++){
    arr.push_back(i);
    if(L==arr.size())out.push_back(arr);
    f(N,L,arr);
    arr.pop_back();
  }
}
 
int sum(const vector<int>&arr,const vector<int>&ids){int v=0;for(size_t i=0;i<ids.size();i++)v+=arr[ids[i]];return v;}
 
bool check(const vector<int>&inp){
  vector<int> e;
  int n=inp.size();
  for(int i=0;i<n;i++)f(n,i+1,e);
  for(int i=0;i<out.size();i++){
    auto&arr=out[i];
    if(0==sum(inp,arr)){for(int i=0;i<arr.size();i++)cout<<inp[arr[i]]<<" ";cout<<endl;return true;}
  }
  return false;
}
 
int main() {
  int inp_arr[]={2,-7,4,8,1}; int n=5;
  vector<int> inp(inp_arr,inp_arr+n);
  cout<<(check(inp)?"true":"false");
  return 0;
}

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