Submission #287042

#	Time	Username	Problem	Language	Result	Execution time	Memory
287042		erray	Awesome Arrowland Adventure (eJOI19_adventure)	C++17	100 / 100	161 ms	14304 KiB

adventure

// author: erray
#include<bits/stdc++.h>
 
using namespace std;
 
int main () {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  vector<int> h(256);
  h['X'] = 4;
  h['N'] = 0;
  h['E'] = 1;
  h['S'] = 2;
  h['W'] = 3;
  int n, m;
  cin >> n >> m;
  vector<string> grid(n);
  for (int i = 0; i < n; ++i) {
    cin >> grid[i];
    for (auto& c : grid[i]) {
      c = h[c];  
    }
  }
  vector<vector<int>> cost(n, vector<int>(m, -1));
  struct pqNode {
    int x, y, c;
    bool operator< (const pqNode& ot) const {
      return c > ot.c;
    }
  };
  const int dx[] = {-1, 0, 1, 0}, dy[] = {0, 1, 0, -1};
  priority_queue<pqNode> pq;
  pq.push(pqNode{0, 0, 0});
  while (!pq.empty()) {
    int x = pq.top().x, y = pq.top().y, c = pq.top().c;
    pq.pop();
    if (cost[x][y] != -1) continue;    
    cost[x][y] = c;
    if (grid[x][y] == 4) {
      continue;
    }
    for (int d = 0; d < 4; ++d) {
      int nw = (int) grid[x][y] + d;
      nw %= 4;
      int nx = x + dx[nw], ny = y + dy[nw];
      if (nx < 0 || ny < 0 || nx >= n || ny >= m) continue; 
      pq.push(pqNode{nx, ny, c + d});
    }  
  }
  cout << cost[n - 1][m - 1] << '\n';
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 12 / 12
• Subtask 4: 16 / 16
• Subtask 5: 50 / 50