Submission #1110750

#	Time	Username	Problem	Language	Result	Execution time	Memory
1110750		epicci23	Arranging Shoes (IOI19_shoes)	C++17	Compilation error	0 ms	0 KiB

shoes

#include "bits/stdc++.h"
using namespace std;
#define int long long
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)x.size()

struct Fenwick{
  vector<int> fw;
  int N;
  Fenwick(int _n){
  	N = _n + 15;
  	fw.assign(N,0);
  }
  void upd(int c){
    for(;c<N;c+=c&-c) fw[c]--;
  }
  int query(int c,int res=0){
  	for(;c;c-=c&-c) res+=fw[c];
  	return res;
  }
};

int64_t count_swaps(vector<int> S){
  int n , ans = 0; 
  n = sz(S) / 2;
  int ar[2 * n + 5];
  for(int i=1;i<=2*n;i++) ar[i] = S[i - 1];
  
  queue<int> q;
  vector<int> pos[n+5];

  Fenwick F(2*n);

  for(int i=1;i<=2*n;i++){
    if(ar[i]<0) q.push(i);
    else pos[ar[i]].push_back(i);
  }
  
  for(int i=1;i<=n;i++) reverse(all(pos[i]));

  while(!q.empty()){
  	int c = q.front();
  	q.pop();
  	int x = pos[-ar[c]].back();
  	pos[-ar[c]].pop_back();
  	F.upd(c + 1);
  	ans += c + F.query(c) - 1;
  	F.upd(x + 1);
  	ans += x + F.query(x) - 1;
  }

  return ans;
}


/*void _(){
  int n,ans=0; cin >> n;
  int ar[2*n+5];
  for(int i=1;i<=2*n;i++) cin >> ar[i];
  
  queue<int> q;
  vector<int> pos[n+5];

  Fenwick F(2*n);

  for(int i=1;i<=2*n;i++){
    if(ar[i]<0) q.push(i);
    else pos[ar[i]].push_back(i);
  }
  
  for(int i=1;i<=n;i++) reverse(all(pos[i]));

  while(!q.empty()){
  	int c = q.front();
  	q.pop();
  	int x = pos[-ar[c]].back();
  	pos[-ar[c]].pop_back();
  	F.upd(c + 1);
  	ans += c + F.query(c) - 1;
  	F.upd(x + 1);
  	ans += x + F.query(x) - 1;
  }

  cout << ans << '\n';
}

int32_t main(){
  ios::sync_with_stdio(0);
  cin.tie(0);
  int tc=1;//cin >> tc;
  while(tc--) _();
}*/

Compilation message (stderr)

/usr/bin/ld: /tmp/ccCtNYaV.o: in function `main':
grader.cpp:(.text.startup+0x2a8): undefined reference to `count_swaps(std::vector<int, std::allocator<int> >)'
collect2: error: ld returned 1 exit status