Submission #786932

#	Time	Username	Problem	Language	Result	Execution time	Memory
786932		MCi	Tracks in the Snow (BOI13_tracks)	C++14	1.67 / 100	676 ms	357896 KiB

tracks

#include<bits/stdc++.h>
#define file "D:\\CWistor\\code"
using namespace std; 

#define ll long long
#define MAX 100100
#define fi first
#define se second
#define ull unsigned long long
#define pii pair<int,int>
#define pll pair<ll,ll>
#define vi vector<int>
#define vl vector<long long>
#define mem(a, b) memset((a), (b), sizeof((a)))
#define all(c) (c).begin(), (c).end()
int n, m, a[4005][4005];
int dx[] = {1, -1, 0, 0};
int dy[] = {0, 0, 1, -1};
int cnt = 0;
void run_with_file()
{
    if (fopen(file".inp", "r"))
    {
        freopen(file".inp", "r", stdin);
        freopen(file".out", "w", stdout);
    }
}
void inp(){
    cin >> n >> m;
    for(int i = 1; i <= n; ++i){
        for(int j = 1; j <= m; ++j){
            char x;
            cin >> x;
            if(x == '.') a[i][j] = 1;
            else a[i][j] = 0;
        }
    }
}
void dfs(int i, int j){
    a[i][j] = 0;
    for(int k = 0; k < 4; ++k){
        int i1 = i + dx[k];
        int j1 = j + dy[k];
        if(i1 >= 1 && i1 <= n && j1 >= 1 && j1 <= m && a[i1][j1] == 1){
            a[i1][j1] = 0;
            dfs(i1, j1);
        }
    }
}
int main()
{
    cin.tie(0)->sync_with_stdio(0);
    run_with_file(); 
    inp();
    if(n == 1 && m == 1){
        if(a[n][m] == 1) cout << 1;
        else cout << 0;
        exit(0);
    }
    for(int i = 1; i <= n; ++i){
        for(int j = 1; j <= m; ++j){
            if(a[i][j] == 1){
                cnt++;
                dfs(i, j);
            }
        }
    }
    cout << cnt;
}

Compilation message (stderr)

tracks.cpp: In function 'void run_with_file()':
tracks.cpp:24:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |         freopen(file".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
tracks.cpp:25:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |         freopen(file".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 1.6666666666666667 / 30
• Subtask 2: 0 / 70