Submission #224182

#	Time	Username	Problem	Language	Result	Execution time	Memory
224182		Bruteforceman	Swap (BOI16_swap)	C++11	68 / 100	904 ms	110840 KiB

swap

#include <bits/stdc++.h>
using namespace std;
using pii = pair <int, int>;
const int maxn = 1e5 + 5;
map <int, int> dp[maxn], op[maxn];
int a[maxn];
int n;

void dfs(int x) {
  int l = x << 1;
  int r = l + 1;
  if(l <= n) dfs(l);
  if(r <= n) dfs(r);
  
  vector <int> imp;
  int cur = x;
  imp.emplace_back(a[x]);
  while(cur > 1) {
    int nxt = cur / 2;
    imp.emplace_back(a[nxt]);
    if(cur & 1) imp.emplace_back(a[cur ^ 1]);
    cur = nxt;
  }
  if(r <= n) {
    for(int y : imp) { 
      vector <pii> opt ({{INT_MAX, INT_MAX}, {INT_MAX, INT_MAX}, {INT_MAX, INT_MAX}});
      for(int i = 0; i <= 1; i++) {
      for(int j = 0; j <= 1; j++) {
        int p = y, q = a[l], s = a[r];
        if(i) swap(p, q);
        if(j) swap(p, s);
        vector <pii> can;
        can.emplace_back(x, p);
        can.emplace_back(dp[l][q], q);
        can.emplace_back(dp[r][s], s);
        sort(can.begin(), can.end());
        if(opt > can) {
          opt = can;
          for(auto w : can) if(w.second == y) dp[x][y] = w.first;
          op[x][y] = j * 2 + i;
        }
      }
    }
    }
  } else if (l <= n) {
    for(int y : imp) {
      vector <pii> opt ({{INT_MAX, INT_MAX}, {INT_MAX, INT_MAX}});
      for(int i = 0; i <= 1; i++) {
      int p = y, q = a[l];
      if(i) swap(p, q);
      vector <pii> can;
      can.emplace_back(x, p);
      can.emplace_back(dp[l][q], q);
      sort(can.begin(), can.end());
      if(opt > can) {
        opt = can;
        for(auto w : can) if(w.second == y) dp[x][y] = w.first;
        op[x][y] = i;
      }
      }
    }
  } else {
    for(int y : imp) {
      dp[x][y] = x;
      op[x][y] = 0;
    }
  }
}

void getOpt(int x) {
  int i = op[x][a[x]] & 1;
  int j = op[x][a[x]] >> 1;
  int l = x << 1;
  int r = l + 1;
  if(i) swap(a[x], a[l]);
  if(j) swap(a[x], a[r]);
  if(l <= n) getOpt(l);
  if(r <= n) getOpt(r);
}

int main() {
  ios_base :: sync_with_stdio (false);
  cin.tie(0);
  cin >> n;
  for(int i = 1; i <= n; i++) {
    cin >> a[i];
  }
  dfs(1);
  getOpt(1);
  for(int i = 1; i <= n; i++) {
    cout << a[i] << ' ';
  }
  cout << endl;
  return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 11 / 11
• Subtask 3: 27 / 27
• Subtask 4: 20 / 20
• Subtask 5: 0 / 32