Submission #649073

#	Time	Username	Problem	Language	Result	Execution time	Memory
649073		anirudh001	Tracks in the Snow (BOI13_tracks)	C++14	0 / 100	612 ms	1048580 KiB

tracks

#include<bits/stdc++.h>
#define ll long long

using namespace std;
const int nm = 1e6;

bool isValid(int x, int y, int n, int m, string snow[]){
    if(x>=0 && x<n && y>=0 && y<m && snow[x][y]!='.')return true;

    return false;
}

int main(){
    #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #endif

    ll h, w;
    cin >> h >> w;

    string snow[h];
    for(int i = 0; i<h; i++)cin >> snow[i];

    vector<vector<int>> depth(h, vector<int>(w));

    deque<pair<int, int>> q;
    q.push_back({0, 0});
    depth[0][0] =1;
    int dx[4] = {0, 0, 1, -1};
    int dy[4] = {1, -1, 0, 0};
    int ans = 0;
    while(!q.empty()){
        int i = q.front().first;
        int j = q.front().second;
        ans = max(depth[i][j], ans);
        q.pop_front();
        for(int k = 0; k<4; k++){
            int x = i + dx[k], y = j + dy[k];
            if(isValid(x, y, h, w, snow) && depth[x][y]==0){
                if(snow[x][y]==snow[i][j]){
                    q.push_front({x, y});
                    depth[x][y] = depth[i][j];
                }
                else{
                    q.push_back({x, y});
                    depth[x][y] = depth[i][j] +1;
                }
            }
        }
    }

    cout << ans << endl;
}

Compilation message (stderr)

tracks.cpp: In function 'int main()':
tracks.cpp:15:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |     freopen("input.txt", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
tracks.cpp:16:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |     freopen("output.txt", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

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