Submission #1251689

#	Time	Username	Problem	Language	Result	Execution time	Memory
1251689		kunzaZa183	Tracks in the Snow (BOI13_tracks)	C++20	78.13 / 100	937 ms	1114112 KiB

tracks

#include <bits/stdc++.h>
using namespace std;
const int mn = 4000;
short vvi[mn][mn];
char vs[mn][mn + 1];
int n, m;
int ct = 0;
vector<pair<int, int>> newones, new2;

const int dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1};
void flood(int x, int y) {
  vvi[x][y] = ct;
  // cout << x << " " << y << "\n";
  for (int i = 0; i < 4; i++) {
    int nx = x + dx[i], ny = y + dy[i];
    if (nx >= 0 && nx < n && ny >= 0 && ny < m) {
      if (vvi[nx][ny] == 0 && vs[nx][ny] != '.') {
        if (vs[nx][ny] == vs[x][y]) {
          vvi[nx][ny] = ct;
          flood(nx, ny);
        } else {
          new2.push_back({nx, ny});
        }
      }
    }
  }
};
int main() {
  // cin.tie(0)->sync_with_stdio(0);
  cin >> n >> m;
  for (int i = 0; i < n; i++)
    cin >> vs[i];

  newones.push_back({0, 0});

  while (!newones.empty()) {
    ct++;

    for (auto [x, y] : newones) {
      flood(x, y);
    }

    new2.swap(newones);
    new2.clear();
  }

  short maxi = 0;
  for (auto &a : vvi)
    for (auto b : a)
      maxi = max(maxi, b);
  cout << maxi << "\n";
}

• Subtask 1: 30 / 30
• Subtask 2: 48.125 / 70