제출 #728720

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
728720		asdfgrace	Mecho (IOI09_mecho)	C++17	100 / 100	198 ms	4156 KiB

mecho

#include <bits/stdc++.h>
using namespace std;
#define DEBUG(x) //x
#define A(x) DEBUG(assert(x))
#define PRINT(x) DEBUG(cerr << x)
#define PV(x) DEBUG(cerr << #x << " = " << x << endl)
#define PAR(x) DEBUG(PRINT(#x << " = { "); for (auto y : x) PRINT(y << ' '); PRINT("}\n");)
#define PAR2(x) DEBUG(PRINT(#x << " = { "); for (auto [y, z] : x) PRINT(y << ',' << z << "  "); PRINT("}\n");)
using i64 = int64_t;
const int INF = 1000000007; //998244353;

struct S {
  int n, k;
  vector<string> a;
  vector<pair<int, int>> hives;
  pair<int, int> origin, dest;
  vector<vector<int>> bdist;
  const array<int, 4> dx = {1, -1, 0, 0};
  const array<int, 4> dy = {0, 0, 1, -1};

  void run() {
    cin >> n >> k;
    a.resize(n);
    for (int i = 0; i < n; ++i) {
      cin >> a[i];
      for (int j = 0; j < n; ++j) {
        if (a[i][j] == 'H') {
          hives.push_back({i, j});
        } else if (a[i][j] == 'M') {
          origin = {i, j};
        } else if (a[i][j] == 'D') {
          dest = {i, j};
        }
      }
    }
  }
  
  void bfs1() {
    queue<array<int, 3>> q;
    vector<vector<bool>> visited(n, vector<bool>(n, false));
    bdist.resize(n, vector<int>(n, INF));
    for (auto p : hives) {
      q.push({p.first, p.second, 0});
      bdist[p.first][p.second] = 0;
      visited[p.first][p.second] = true;
    }
    while (!q.empty()) {
      int x = q.front()[0];
      int y = q.front()[1];
      int d = q.front()[2];
      q.pop();
      for (int i = 0; i < 4; ++i) {
        int x2 = x + dx[i];
        int y2 = y + dy[i];
        if (ok(x2, y2) && !visited[x2][y2] && a[x2][y2] != 'D') {
          q.push({x2, y2, d + 1});
          visited[x2][y2] = true;
          bdist[x2][y2] = d + 1;
        }
      }
    }
    DEBUG(
    for (auto arr : bdist) {
      PAR(arr);
    }
    )
    PRINT('\n');
  }
  
  void bs() {
    if (!safe(0)) {
      cout << -1 << '\n';
      return;
    }
    int h = n * n, l = 0;
    while (h - 1 > l) {
      int m = (h + l) / 2;
      if (safe(m)) l = m;
      else h = m - 1;
    }
    cout << (safe(h) ? h : l) << '\n';
  }
  
  bool safe(int t) {
    PV(t);
    queue<array<int, 3>> q;
    vector<vector<bool>> visited(n, vector<bool>(n, false));
    q.push({origin.first, origin.second, 0});
    visited[origin.first][origin.second] = true;
    if (bdist[origin.first][origin.second] <= t) return false;
    while (!q.empty()) {
      int x = q.front()[0];
      int y = q.front()[1];
      int d = q.front()[2];
      q.pop();
      for (int i = 0; i < 4; ++i) {
        int x2 = x + dx[i];
        int y2 = y + dy[i];
        if (ok(x2, y2) && !visited[x2][y2] && a[x2][y2] != 'H'
          && (d + 1) / k + t < bdist[x2][y2]) {
          q.push({x2, y2, d + 1});
          visited[x2][y2] = true;
        }
      }
    }
    DEBUG(
    for (auto arr : visited) {
      PAR(arr);
    }
    )
    PRINT('\n');
    return visited[dest.first][dest.second];
  }
  
  bool ok(int x, int y) {
    return x >= 0 && y >= 0 && x < n && y < n && a[x][y] != 'T';
  }
};

int main() {
  ios::sync_with_stdio(0); cin.tie(0);
  auto sol = make_unique<S>();
  sol->run();
  sol->bfs1();
  sol->bs();
}

• Subtask 1: 100 / 100