Submission #1002484

#	Time	Username	Problem	Language	Result	Execution time	Memory
1002484		MilosMilutinovic	Swap (BOI16_swap)	C++14	48 / 100	1066 ms	139020 KiB

swap

#include <bits/stdc++.h>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  vector<int> a(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    --a[i];
  }
  vector<vector<int>> vals(n);
  vector<unordered_map<int, bool>> seen(n);
  function<void(int, int)> Build = [&](int i, int v) {
    if (i >= n || seen[i][v]) {
      return;
    }
    seen[i][v] = true;
    vals[i].push_back(v);
    int L = i * 2 + 1, R = i * 2 + 2;
    if (L >= n) {
      return;
    }
    if (R >= n) {
      if (v < a[L]) {
        Build(L, a[L]);
      } else {
        Build(L, v);
      }
      return;
    }
    if (v <= a[L] && v <= a[R]) {
      Build(L, a[L]);
      Build(R, a[R]);
    } else if (a[L] <= v && a[L] <= a[R]) {
      Build(L, v);
      Build(R, a[R]);
    } else {
      Build(L, a[L]);
      Build(R, v);
      Build(L, v);
      Build(R, a[L]);
    }
  };
  Build(0, a[0]);
  for (int i = 0; i < n; i++) {
    sort(vals[i].begin(), vals[i].end());
    vals[i].erase(unique(vals[i].begin(), vals[i].end()), vals[i].end());
  }
  vector<vector<vector<int>>> dp(n);
  vector<map<int, int>> idx(n);
  auto Merge = [&](int x, vector<int> va, vector<int> vb) {
    vector<int> v(1, x);
    int pa = 0, pb = 0;
    for (int pw = 1; pa < (int) va.size(); pw *= 2) {
      for (int iter = 0; iter < pw; iter++) {
        if (pa < (int) va.size()) {
          v.push_back(va[pa]);
          pa += 1;
        } else {
          break;
        }
      }
      for (int iter = 0; iter < pw; iter++) {
        if (pb < (int) vb.size()) {
          v.push_back(vb[pb]);
          pb += 1;
        } else {
          break;
        }
      }
    }
    return v;
  };
  function<vector<int>(int, int)> Solve = [&](int i, int v) {
    if (i >= n) {
      return vector<int>{};
    }
    if (!idx[i][v]) {
      idx[i][v] = (int) dp[i].size();
      dp[i].push_back({});
    }
    int p = idx[i][v];
    if (!dp[i][p].empty()) {
      return dp[i][p];
    }
    int L = i * 2 + 1, R = i * 2 + 2;
    if (L >= n) {
      return dp[i][p] = {v};
    }
    if (R >= n) {
      if (v < a[L]) {
        dp[i][p] = Merge(v, Solve(L, a[L]), {});
      } else {
        dp[i][p] = Merge(a[L], Solve(L, v), {});
      }
      return dp[i][p];
    }
    if (v <= a[L] && v <= a[R]) {
      dp[i][p] = Merge(v, Solve(L, a[L]), Solve(R, a[R]));
    } else if (a[L] <= v && a[L] <= a[R]) {
      dp[i][p] = Merge(a[L], Solve(L, v), Solve(R, a[R]));
    } else {
      dp[i][p] = min(Merge(a[R], Solve(L, a[L]), Solve(R, v)), Merge(a[R], Solve(L, v), Solve(R, a[L])));
    }
    return dp[i][p];
  };
  vector<int> dep(n);
  for (int i = 1; i < n; i++) {
    dep[i] = dep[(i - 1) / 2] + 1;
  }
  vector<vector<int>> all(n);
  for (int i = 0; i < n; i++) {
    all[dep[i]].push_back(i);
  }
  for (int d = n - 1; d >= 0; d--) {
    for (int i : all[d]) {
      for (int v : vals[i]) {
        Solve(i, v);
      }
    }
    if (d + 1 < n) {
      for (int i : all[d + 1]) {
        vector<vector<int>>{}.swap(dp[i]);
        idx[i].clear();
      }
    }
  }
  vector<int> res;
  for (int i = 0; i < (int) vals[0].size(); i++) {
    if (vals[0][i] == a[0]) {
      res = dp[0][i];
    }
  }
  for (int i = 0; i < (int) res.size(); i++) {
    cout << res[i] + 1 << " ";
  }
  cout << '\n';
  return 0;
}

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