Submission #879574

#	Time	Username	Problem	Language	Result	Execution time	Memory
879574		iskhakkutbilim	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	338 ms	282448 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace std;
using namespace __gnu_pbds;
 
typedef int64_t ll;
typedef string str;
 
#define ordered_set tree <int, null_type, less <int>, rb_tree_tag, tree_order_statistics_node_update>
 
long long count_swaps(vector <int> S) {
  int n = (int)S.size();
  ll ans = 0;
  for (int i = 0; i < n; ++i) {
    S[i] += n;
  }
  vector <deque <int>> pos(2 * n + 1);
  vector <bool> used(n, false);
  ordered_set st;
  for (int i = 0; i < n; ++i) {
    pos[S[i]].push_back(i);
  }
  for (int i = 0; i + 1 < n; ++i) {
    if (used[i]) {
      continue;
    }
    if (S[i] > n) {
      int left = S[i] - n - 2 * (S[i] - n) + n, right = S[i];
      int from = pos[left].front();
      ans += from - i;
      ans -= (int)st.order_of_key(from + 1) - (int)st.order_of_key(i);
      st.insert(i), st.insert(from);
      used[i] = true, used[from] = true;
      pos[left].pop_front(), pos[right].pop_front();
    } else {
      int left = S[i], right = S[i] - n - 2 * (S[i] - n) + n;
      int from = pos[right].front();
      ans += from - i - 1;
      ans -= (int)st.order_of_key(from + 1) - (int)st.order_of_key(i);
      st.insert(i), st.insert(from);
      used[i] = true, used[from] = true;
      pos[left].pop_front(), pos[right].pop_front();
    }
  }
  return ans;
}

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