제출 #1306452

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1306452		baodat	Arranging Shoes (IOI19_shoes)	C++20	10 / 100	1 ms	348 KiB

shoes

#include <bits/stdc++.h>
using namespace std;
#define ll long long 
#define FOR(i, l, r) for(int i = l; i <= r; i++)
#define FORD(i, l, r) for(int i = l; i >= r; i--)
#define all(x) (x).begin(), (x).end()
struct BIT{
  int n;
  vector<int> bit;
  BIT(int __n = 0){
    init(__n);
  }
  void init(int __n = 0){
    n = __n;
    bit.assign(n + 5, 0);
  }
  void update(int i, int v){
    ++i;
    while(i <= n){
      bit[i] += v;
      i += i &-i;
    }
  }
  int query(int i){
    ++i;
    int ans = 0;
    while(i > 0){
      ans += bit[i];
      i -= i &-i;
    }
    return ans;
  }
  int query(int l, int r){
    return query(r) - query(l - 1);
  }
};

ll count_swaps(vector<int> a){
  int m = a.size();              
  int maxi = 0;
  for (int x : a) maxi = max(maxi, abs(x));
  vector<int> last(maxi + 1, -1);
  vector<int> match(m, -1);
  for (int i = 0; i < m; ++i) {
    int x = abs(a[i]);
    if (last[x] == -1) last[x] = i;
    else {
      match[i] = last[x];
      match[last[x]] = i;
    }
  }

  BIT bit(m);
  FOR(i, 0, m - 1)bit.update(i, 1);

  vector<char> used(m, 0);
  ll ans = 0;
  FOR(i, 0, m - 1){
    if (used[i]) continue;
    int j = match[i];
    if (j == -1) continue;     
    if (i > j) continue;     
    ans += bit.query(i + 1, j - 1);
    if (a[i] > 0) ++ans;
    used[i] = used[j] = 1;
    bit.update(i, -1);
    bit.update(j, -1);
  }

  return ans;
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 15