Submission #1271227

#	Time	Username	Problem	Language	Result	Execution time	Memory
1271227		strange420	World Map (IOI25_worldmap)	C++20	22 / 100	29 ms	4164 KiB

worldmap

#include "worldmap.h"
#include <algorithm>
#include <iostream>
#include <functional>
#include <utility>
#include <cmath>

std::vector<std::vector<int>> test(int N) {
  std::vector<std::vector<int>> ans(2 * N, std::vector<int>(2 * N, 1));
  return ans;
}

std::vector<std::vector<int>> solve_subtask1(int N, int M, std::vector<int> A, std::vector<int> B) {
  int K = (N+2)/2;
  std::vector<std::vector<int>> ans(K, std::vector<int>(K, 0));
  for (int i=0; i<K; i++) {
    int x = i+1;
    for (int j=0; j<K; j++, x++) {
      ans[i][j] = std::min(x, N);
    }
  }
  return ans;
}

std::vector<std::vector<int>> solve_subtask2(int N, int M, std::vector<int> A, std::vector<int> B) {
  std::vector<int> asd, visited(N, 0);
  std::vector<std::vector<int>> adj_list(N), ans;
  for (int i=0; i<M; i++) {
    adj_list[A[i]-1].push_back(B[i]-1);
    adj_list[B[i]-1].push_back(A[i]-1);
  }
  std::function<void(int, int, std::vector<std::vector<int>>&, std::vector<int>&)> dfs;
  dfs = [&](int p, int u, std::vector<std::vector<int>>& adj_list, std::vector<int>& asd) {
    if (visited[u]) return;
    visited[u] = 1;
    asd.push_back(u+1);
    for (int v: adj_list[u]) {
      dfs(u, v, adj_list, asd);
      asd.push_back(u+1);
    }
  };
  dfs(-1, 0, adj_list, asd);
  for (int i=0; i<asd.size(); i++) {
    ans.push_back(asd);
  }
  return ans;
}

std::vector<std::vector<int>> solve_subtask3(int N, int M, std::vector<int> A, std::vector<int> B) {
  int K = N + (N&1);
  std::vector<std::vector<int>> ans(K);
  std::vector<std::pair<int, int>> pairs;
  for (int i=0; i<N; i++) {
    for (int j=i+1; j<N; j++) {
      pairs.push_back(std::make_pair(i+1, j+1));
    }
  }

  for (int i=0; i<K; i++) {
    while(ans[i].size() != K) {
      if (pairs.size() == 0) {
        ans[i].push_back(1);
        ans[i].push_back(1);
      } else {
        std::pair<int, int> temp = pairs.back();
        pairs.pop_back();
        ans[i].push_back(temp.first);
        ans[i].push_back(temp.second);
      }
    }
  }
  return ans;
}

std::vector<std::vector<int>> solve_subtask4(int N, int M, std::vector<int> A, std::vector<int> B) {
  std::vector<std::pair<int,int>> adj_list;
  for (int i=0; i<M; i++) {
    if (A[i] == 1) continue;
    adj_list.push_back(std::pair(A[i], B[i]));
  }

  int temp = std::sqrt(adj_list.size()) + 1;
  int K = temp * 3 - 1, pt = 0;
  std::vector<std::vector<int>> ans(K);
  for (auto p: adj_list) {
    ans[pt].push_back(p.first);
    ans[pt].push_back(p.second);

    if (ans[pt].size() == K) {
      pt++;
      for (int i=0; i<K; i++) ans[pt].push_back(1);
      pt++;
    } else {
      ans[pt].push_back(1);
    }
  }

  for (; pt<K; pt++) {
    while (ans[pt].size() < K) {
      ans[pt].push_back(1);
    }
  }
  return ans;
}

std::vector<std::vector<int>> solve_subtask5(int N, int M, std::vector<int> A, std::vector<int> B) {
  std::vector<std::vector<int>> adj_list(N+1);
  for (int i=0; i<M; i++) {
    adj_list[A[i]].push_back(B[i]);
    adj_list[B[i]].push_back(A[i]);
  }
  for (int i=1; i<=N; i++) {
    adj_list[0].push_back(i);
  }

  std::vector<int> path;
  std::function<void(std::vector<int>&, std::vector<std::vector<int>>&, int, std::vector<int>&)> tsp;
  tsp = [&](std::vector<int>& _path, std::vector<std::vector<int>>& adj_list, int u, std::vector<int>& visited) {
    if (visited[u] || path.size() == N) return;
    visited[u] = true;
    _path.push_back(u);

    if (_path.size() > path.size()) path = _path;
    for (int v: adj_list[u]) {
      tsp(_path, adj_list, v, visited);
    }

    _path.resize(_path.size()-1);
    visited[u] = false;
  };

  std::vector<int> temp, visited(N+1, 0);
  tsp(temp, adj_list, 0, visited);

  for (int x: path) {
    visited[x] = 1;
  }

  while(true) {
    for (int i=1; i<=N; i++) {
      if (visited[i]) continue;

      for (int v: adj_list[i]) {
        if (visited[v]) {
          bool flag = false;
          std::vector<int> temp;
          for (int x: path) {
            temp.push_back(x);
            if (x == v && !flag) {
              temp.push_back(i);
              temp.push_back(v);
              flag = true;
            }
          }
          visited[i] = 1;
          path = temp;
          break;
        }
      }
    }

    bool flag = true;
    for (int x: visited) {
      if (!x) flag = false;
    }
    if (flag) break;
  }

  std::vector<int> partial;
  for (int i=2; i<path.size(); i++) {
    int current = path[i-1];
    int next = path[i];

    for (int x: adj_list[current]) {
      if (next == x) continue;
      partial.push_back(x);
      partial.push_back(current);
    }
    partial.push_back(next);
  }

  int K = (partial.size() + 1) / 2;
  std::vector<std::vector<int>> ans(K);
  for (int i=0; i<K; i++) {
    for (int j=0; j<K; j++) {
      ans[i].push_back(partial[i+j]);
    }
  }
  return ans;
}

std::vector<std::vector<int>> solve_subtask6(int N, int M, std::vector<int> A, std::vector<int> B) {
  return test(N);
}

std::vector<std::vector<int>> create_map(int N, int M, std::vector<int> A, std::vector<int> B) {
  bool subtask1_constraint = true;
  for (int i = 0; i < M; i++) {
    if (A[i] == i+1 && B[i] == i+2) continue;
    subtask1_constraint = false;
  }

  std::vector<int> temp;
  for (int i = 0; i < M; i++) {
    if (A[i] == 1) temp.push_back(B[i]);
  }
  bool subtask4_constraint = temp.size() == N-1;

  if (M == N-1 && subtask1_constraint) {
    return solve_subtask1(N, M, A, B);
  } else if (M == N-1) {
    return solve_subtask2(N, M, A, B);
  } else if (M == N*(N-1)/2) {
    return solve_subtask3(N, M, A, B);
  } else if (subtask4_constraint) {
    return solve_subtask4(N, M, A, B);
  } else if (N <= 15) {
    return solve_subtask5(N, M, A, B);
  } else {
    return solve_subtask6(N, M, A, B);
  }
}

• Subtask 0: 0 / 0
• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 7 / 7
• Subtask 4: 0 / 8
• Subtask 5: 0 / 14
• Subtask 6: 0 / 56