oj.uz

Submission #494357

# Submission time Handle Problem Language Result Execution time Memory
494357 2021-12-15T09:54:43 Z MilosMilutinovic Portals (BOI14_portals) C++14
20 / 100
 17 ms 6092 KB 
#include <bits/stdc++.h>

using namespace std;

const int dx[] = {1, -1, 0, 0};
const int dy[] = {0, 0, 1, -1};

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m;
  cin >> n >> m;
  vector<string> s(n);
  for (int i = 0; i < n; i++) {
    cin >> s[i];
  }
  int sx, sy, cx, cy;
  vector<vector<int>> wall(n, vector<int>(m, 1e7));
  vector<pair<int, int>> v;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (s[i][j] == 'S') {
        sx = i;
        sy = j;
      }
      if (s[i][j] == 'C') {
        cx = i;
        cy = j;
      }
      if (s[i][j] == '#') {
        v.emplace_back(i, j);
        wall[i][j] = -1;
      }
    }
  }
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (s[i][j] == '#') continue;
      if (i == 0 || i == n - 1 || j == 0 || j == m - 1) {
        v.emplace_back(i, j);
        wall[i][j] = 0;
      }
    }
  }
  for (int i = 0; i < v.size(); i++) {
    int x = v[i].first, y = v[i].second;
    for (int d = 0; d < 4; d++) {
      int ni = x + dx[d], nj = y + dy[d];
      if (ni >= 0 && ni < n && nj >= 0 && nj < m && wall[ni][nj] > wall[x][y] + 1) {
        wall[ni][nj] = wall[x][y] + 1;
        v.emplace_back(ni, nj);
      }
    }
  }
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      assert(wall[i][j] != 1e7);
    }
  }
  vector<vector<pair<int, int>>> up(n, vector<pair<int, int>>(m));
  vector<vector<pair<int, int>>> down(n, vector<pair<int, int>>(m));
  vector<vector<pair<int, int>>> left(n, vector<pair<int, int>>(m));
  vector<vector<pair<int, int>>> right(n, vector<pair<int, int>>(m));
  //up
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (s[i][j] != '#') {
        if (i == 0 || up[i - 1][j] == make_pair(-1, -1)) {
          up[i][j] = make_pair(i, j);
        } else {
          up[i][j] = up[i - 1][j];
        }
      } else {
        up[i][j] = make_pair(-1, -1);
      }
    }
  }
  //down
  for (int i = n - 1; i >= 0; i--) {
    for (int j = 0; j < m; j++) {
      if (s[i][j] != '#') {
        if (i == n - 1 || down[i + 1][j] == make_pair(-1, -1)) {
          down[i][j] = make_pair(i, j);
        } else {
          down[i][j] = down[i + 1][j];
        }
      } else {
        down[i][j] = make_pair(-1, -1);
      }
    }
  }
  //left
  for (int j = 0; j < m; j++) {
    for (int i = 0; i < n; i++) {
      if (s[i][j] != '#') {
        if (j == 0 || left[i][j - 1] == make_pair(-1, -1)) {
          left[i][j] = make_pair(i, j);
        } else {
          left[i][j] = left[i][j - 1];
        }
      } else {
        left[i][j] = make_pair(-1, -1);
      }
    }
  }
  //right
  for (int j = m - 1; j >= 0; j--) {
    for (int i = 0; i < n; i++) {
      if (s[i][j] != '#') {
        if (j == m - 1 || right[i][j + 1] == make_pair(-1, -1)) {
          right[i][j] = make_pair(i, j);
        } else {
          right[i][j] = right[i][j + 1];
        }
      } else {
        right[i][j] = make_pair(-1, -1);
      }
    }
  }
  vector<vector<vector<tuple<int, int, int>>>> g(n, vector<vector<tuple<int, int, int>>>(m));
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (s[i][j] == '#') continue;
      bool ok = false;
      if (up[i][j] == make_pair(i, j)) {
        ok = true;
      }
      if (down[i][j] == make_pair(i, j)) {
        ok = true;
      }
      if (left[i][j] == make_pair(i, j)) {
        ok = true;
      }
      if (right[i][j] == make_pair(i, j)) {
        ok = true;
      }
      if (ok || false) {
        for (auto nn : {up[i][j], down[i][j], left[i][j], right[i][j]}) {
          if (nn == make_pair(-1, -1)) {
            continue;
          }
          g[i][j].emplace_back(nn.first, nn.second, wall[i][j] + 1);
        }
      }
      for (int foo = 0; foo < 4; foo++) {
        int ni = i + dx[foo], nj = j + dy[foo];
        if (ni >= 0 && ni < n && nj >= 0 && nj < m && s[ni][nj] != '#') {
          g[i][j].emplace_back(ni, nj, 1);
        }
      }
    }
  }
  set<tuple<int, int, int>> q;
  q.insert({0, sx, sy});
  vector<vector<int>> dist(n, vector<int>(m, 1e9));
  dist[sx][sy] = 0;
  while (!q.empty()) {
    auto it = *q.begin();
    int x = get<1>(it);
    int y = get<2>(it);
    int dd = get<0>(it);
    q.erase(q.begin());
    if (dd > dist[x][y]) {
      continue;
    }
    for (auto c : g[x][y]) {
      int w = get<2>(c);
      if (dist[get<0>(c)][get<1>(c)] > dist[x][y] + w) {
        dist[get<0>(c)][get<1>(c)] = dist[x][y] + w;
        q.insert({dist[get<0>(c)][get<1>(c)], get<0>(c), get<1>(c)});
      }
    }
  }
  int ans = dist[cx][cy];
  cout << (ans == 1e9 ? -1 : ans) << '\n';
  return 0;
}

Compilation message

portals.cpp: In function 'int main()':
portals.cpp:45:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |   for (int i = 0; i < v.size(); i++) {
      |                   ~~^~~~~~~~~~
portals.cpp:174:24: warning: 'cy' may be used uninitialized in this function [-Wmaybe-uninitialized]
  174 |   int ans = dist[cx][cy];
      |                        ^
portals.cpp:156:14: warning: 'sy' may be used uninitialized in this function [-Wmaybe-uninitialized]
  156 |   dist[sx][sy] = 0;
      |              ^
portals.cpp:156:10: warning: 'sx' may be used uninitialized in this function [-Wmaybe-uninitialized]
  156 |   dist[sx][sy] = 0;
      |          ^
portals.cpp:174:20: warning: 'cx' may be used uninitialized in this function [-Wmaybe-uninitialized]
  174 |   int ans = dist[cx][cy];
      |                    ^

Subtask #1
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 1 ms 332 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 0 ms 204 KB Output is correct
10 Incorrect 0 ms 204 KB Output isn't correct

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 332 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 2 ms 588 KB Output is correct
10 Incorrect 1 ms 588 KB Output isn't correct
11 Halted 0 ms 0 KB -

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 14 ms 5700 KB Output is correct
6 Correct 16 ms 5908 KB Output is correct
7 Correct 17 ms 6064 KB Output is correct
8 Correct 12 ms 6092 KB Output is correct

Subtask #4
0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 0 ms 332 KB Output is correct
9 Correct 1 ms 588 KB Output is correct
10 Incorrect 1 ms 588 KB Output isn't correct
11 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 1 ms 332 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 1 ms 588 KB Output is correct
10 Incorrect 1 ms 588 KB Output isn't correct
11 Halted 0 ms 0 KB -