Submission #283121

#	Time	Username	Problem	Language	Result	Execution time	Memory
283121		catalystgma	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	367 ms	274136 KiB

shoes

#include <bits/stdc++.h>
#define ll long long
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pli pair<ll,int>
#define pil pair<int,ll>
#define fi first
#define se second
#define inf (INT_MAX/2-1)
#define infl (1LL<<60)
#define vi vector<int>
#define vl vector<ll>
#define pb push_back
#define sz(a) (int)(a).size()
#define all(a) begin(a),end(a)
#define y0 y5656
#define y1 y7878
#define y2 y9090
#define aaa system("pause");
#define dbg(x) cerr<<(#x)<<": "<<(x)<<'\n',aaa
#define dbga(x,n) cerr<<(#x)<<"[]: ";for(int _=0;_<n;_++)cerr<<x[_]<<' ';cerr<<'\n',aaa
#define dbgs(x) cerr<<(#x)<<"[stl]: ";for(auto _:x)cerr<<_<<' ';cerr<<'\n',aaa
#define dbgp(x) cerr<<(#x)<<": "<<x.fi<<' '<<x.se<<'\n',aaa
#define maxn 200000
#include "shoes.h"

using namespace std;

struct AIB {
  AIB () {}
  int yy[maxn+5];
  int lsb (int x) {
    return x&(-x);
  }
  void upd (int n, int x, int amt) {
    x++; ///index 0 -> 1
    for (; x <= n; x += lsb(x)) yy[x] += amt;
  }
  int qry (int x) {
    int ans = 0;
    x++; ///index 0 -> 1
    for (; x > 0; x -= lsb(x)) ans += yy[x];
    return ans;
  }
  int qryrg (int l, int r) {
    return qry(r) - qry(l-1);
  }
};

AIB aib;
stack<int> stkP[maxn+5], stkM[maxn+5];

ll count_swaps (vi v) {
  int n = sz(v);
  int i, j, z;
  ll ans = 0;
  for (i = n-1; i >= 0; i--)
    if (v[i] > 0) stkP[v[i]].push(i);
    else stkM[-v[i]].push(i);
  for (i = 0; i < n; i++) {
    if (aib.qryrg(i, i) == 1) continue; ///deja mutat
    if (v[i] < 0) {
      while (!stkP[-v[i]].empty() && stkP[-v[i]].top() < i) stkP[-v[i]].pop();
      if (!stkP[-v[i]].empty()) {
        z = stkP[-v[i]].top();
        ans += z-i-1 - aib.qryrg(i+1, z); ///in aib retii ce ai sters deja
        aib.upd(n, z, 1);
        stkP[-v[i]].pop();
      }
    } else {
      while (!stkM[v[i]].empty() && stkM[v[i]].top() < i) stkM[v[i]].pop();
      if (!stkM[v[i]].empty()) {
        z = stkM[v[i]].top();
        ans += z-i - aib.qryrg(i, z);
        aib.upd(n, z, 1);
        stkM[v[i]].pop();
      }
    }
  }
  return ans;
}

//int main () {
//  int n; cin >> n;
//  int i, j, z;
//  vi v(n*2);
//  for (i = 0; i < 2*n; i++) cin >> v[i];
//  cout << count_swaps(v);
//  return 0;
//}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:55:10: warning: unused variable 'j' [-Wunused-variable]
   55 |   int i, j, z;
      |          ^

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 15 / 15
• Subtask 5: 20 / 20
• Subtask 6: 15 / 15