Submission #1120737

#	Time	Username	Problem	Language	Result	Execution time	Memory
1120737		Mamedov	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	607 ms	112332 KiB

tracks

#pragma GCC optimize ("O3")
#include <bits/stdc++.h>
//#include<ext/pb_ds/assoc_container.hpp>
//#include<ext/pb_ds/tree_policy.hpp>
#define pii pair<int, int>
#define piii pair<pii, int>
#define vi vector<int>
#define vll vector<ll>
#define vvi vector<vi>
#define vpii vector<pii>
#define vvpii vector<vpii>
#define f first
#define s second
#define oo 1000000001
#define eb emplace_back
#define pb push_back
#define mpr make_pair
#define size(v) (int)v.size()
#define ln '\n'
#define ull unsigned long long
#define ll long long
#define all(v) v.begin(), v.end()
#define iospeed ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)
//#define pbase 361549
//#define imod 1073737591
//#define uimod 2147479307u
//#define llmod 292187309552789533ll


using namespace std;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

//using namespace __gnu_pbds;
//template <typename T>
//using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

template <typename T>
void show(vector<T> &v) {
  for (T i : v) {
    cout << i << ' ';
  }
  cout << ln;
}

int dx[] = {1, -1, 0, 0};
int dy[] = {0, 0, 1, -1};
void solve() {
  int h, w;
  cin >> h >> w;
  vector<string>s(h);
  for (string &r : s) {
    cin >> r;
  }
  deque<array<int, 2>>q;
  vvi dist(h, vi(w, 0));
  q.push_back({0, 0});
  dist[0][0] = 1;
  int res = 1;
  while (!q.empty()) {
    auto [x, y] = q.front();
    res = max(res, dist[x][y]);
    q.pop_front();
    for (int i = 0; i < 4; ++i) {
      int nx = x + dx[i];
      int ny = y + dy[i];
      if (nx >= 0 && nx < h && ny >= 0 && ny < w && !dist[nx][ny] && s[nx][ny] != '.') {
        dist[nx][ny] = dist[x][y];
        if (s[nx][ny] == s[x][y]) {
          q.push_front({nx, ny});
        } else {
          ++dist[nx][ny];
          q.push_back({nx, ny});
        }
      }
    }
  }
  cout << res << ln;
}
int main() {
  iospeed;
  solve();
  return 0;
}

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