Submission #389922

#	Time	Username	Problem	Language	Result	Execution time	Memory
389922		null_awe	Tracks in the Snow (BOI13_tracks)	C++14	100 / 100	947 ms	112080 KiB

tracks

#include <bits/stdc++.h>
using namespace std;

vector<int> dx{-1, 1, 0, 0}, dy{0, 0, -1, 1};

int main() {
  int h, w;
  cin >> h >> w;
  vector<string> field(h);
  vector<vector<int>> rank(h, vector<int>(w, 0));
  for (int i = 0; i < h; ++i) cin >> field[i];
  int m = 1;
  rank[0][0] = 1;
  deque<pair<int, int>> q;
  q.push_back({0, 0});
  while (!q.empty()) {
    pair<int, int> s = q.front();
    m = max(m, rank[s.first][s.second]);
    q.pop_front();
    for (int i = 0; i < 4; ++i) {
      int x = s.first + dx[i], y = s.second + dy[i];
      if (x < 0 || y < 0 || x >= h || y >= w || rank[x][y] > 0 || field[x][y] == '.') continue;
      int r = rank[s.first][s.second];
      if (field[s.first][s.second] == field[x][y]) {
        q.push_front({x, y});
        rank[x][y] = r;
      } else {
        q.push_back({x, y});
        rank[x][y] = r + 1;
      }
    }
  }
  cout << m;
  return 0;
}

• Subtask 1: 30 / 30
• Subtask 2: 70 / 70