Submission #1321711

#	Time	Username	Problem	Language	Result	Execution time	Memory
1321711		maniikk	Tracks in the Snow (BOI13_tracks)	C++17	0 / 100	1302 ms	1114112 KiB

tracks

#include <bits/stdc++.h>
#pragma GCC Optimize("Ofast")
using namespace std;
#define fast_cin() ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
int depth[4005][4005];
int main()
{
    fast_cin();
    #ifndef ONLINE_JUDGE
    freopen("C:\\Personal\\dsa-prep\\input.txt", "r", stdin);
    freopen("C:\\Personal\\dsa-prep\\output.txt", "w", stdout);
    #endif
    
    int h, w;
    cin >> h >> w;
    vector<string> s;
    for (int i = 0; i < h; i++)
    {
        string temp;
        cin >> temp;
        s.emplace_back(temp);
    }
    using cell = pair<int, int>;
    deque<cell> q;
    depth[0][0] = 1;
    q.push_back({0, 0});
    vector<cell> dir = {{-1, 0}, {1, 0}, {0, -1}, {0, 1}};
    auto inside = [&](int x, int y)
    {
        return x >= 0 && x < h && y >= 0 && y < w && s[x][y] != '.';
    };

    int ans = 1;
    while (!q.empty())
    {
        auto [x, y] = q.front();
        q.pop_front();
        ans = max(ans, depth[x][y]);
        for (auto [dx, dy] : dir)
        {
            int nx = x + dx, ny = y + dy;
            if (inside(nx, ny) && depth[nx][ny] == 0)
            {
                
                if (s[x][y] == s[nx][ny])
                {
                    depth[nx][ny] = depth[x][y];
                    q.push_front({nx, ny});
                }   
                else 
                {
                    depth[nx][ny] = depth[x][y] + 1;
                    q.push_back({nx, ny});
                }
            }
        }
    }

    cout << ans << endl;
}

Compilation message (stderr)

tracks.cpp: In function 'int main()':
tracks.cpp:10:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 |     freopen("C:\\Personal\\dsa-prep\\input.txt", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tracks.cpp:11:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |     freopen("C:\\Personal\\dsa-prep\\output.txt", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 30
• Subtask 2: 0 / 70