제출 #1305820

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1305820		ayaz	Arranging Shoes (IOI19_shoes)	C++20	50 / 100	100 ms	12160 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
#define isz(x) (int)x.size()
long long count_swaps(std::vector<int> s) {
  vector<int> a = s;
  int n = isz(a);
  #define int long long
  bool ok = true;
  set<int> st;
  for (int i = 0; i < n / 2; i++) {
    ok &= (a[i] + a[i + n / 2] == 0);
    ok &= (a[i] < 0);
    st.insert(abs(a[i]));
  }
  if (ok) {
    return (n / 2) * (n / 2 - 1) / 2;
  }
  if (isz(st) == 1) {
    int ans = 0;
    set<int> pos[2];
    for (int i = 0; i < n; i++) {
      pos[a[i] < 0 ? 0 : 1].insert(i);
    }
    for (int i = 0; i < n; i++) {
      if (i % 2 == 0 && a[i] > 0) {
        auto it = pos[0].upper_bound(i);
        ans += *it - i;
        swap(a[i], a[*it]);
        pos[0].erase(it);
        pos[1].erase(pos[1].find(i));
        pos[0].insert(i);
        pos[1].insert(*it);
        continue;
      }
      if (i % 2 == 1 && a[i] < 0) {
        auto it = pos[1].upper_bound(i);
        ans += *it - i;
        swap(a[i], a[*it]);
        pos[1].erase(it);
        pos[0].erase(pos[0].find(i));
        pos[1].insert(i);
        pos[0].insert(*it);
      }
    }
    return ans;
  }
  if (n == 2) {
    return (a[0] > 0);
  }
  a = s;
  int ans = 0;
  for (int i = 0; i < n; i++) {
    if (i % 2 == 0 && a[i] > 0) {
      int d = 1e9;
      for (int j = i + 1; j < n; j++) {
        if (a[j] + a[i] == 0) {
          d = j;
          break;
        }
      }
      ans += (d - i);
      for (int j = d; j > i; j--) swap(a[j], a[j - 1]);
      continue;
    }
    if (i % 2 == 1 && (a[i] < 0 || (a[i - 1] + a[i]) != 0)) {
      int d = 1e9;
      for (int j = i + 1; j < n; j++) {
        if (a[j] + a[i - 1] == 0) {
          d = j;
          break;
        }
      }
      ans += (d - i);
      for (int j = d; j > i; j--) swap(a[j], a[j - 1]);
    }
  }
  for (int i = 0; i < n; i += 2) {
    ans += (a[i] > 0);
  }
  return ans;
}

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