Submission #877686

#	Time	Username	Problem	Language	Result	Execution time	Memory
877686		Beerus13	Tracks in the Snow (BOI13_tracks)	C++14	100 / 100	581 ms	59188 KiB

tracks

#include <bits/stdc++.h>
using namespace std;
#define ll long long
const int N = 4e3 + 5;

int h, w;
string s[N];
int dx[] = {-1, 0, 0, 1};
int dy[] = {0, -1, 1, 0};
bool vs[N][N];
queue<pair<int, int>> q[2];

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    cin >> h >> w;
    for(int i = 0; i < h; ++i) cin >> s[i];
    bool cur = (s[0][0] == 'F');
    vs[0][0] = 1;
    q[cur].emplace(0, 0);
    int cnt = 0;
    while(q[0].size() || q[1].size()) {
        while(q[cur].size()) {
            auto [u, v] = q[cur].front(); q[cur].pop();
            for(int i = 0; i < 4; ++i) {
                int x = u + dx[i];
                int y = v + dy[i];
                if(x < 0 || x >= h || y < 0 || y >= w) continue;
                if(vs[x][y] || s[x][y] == '.') continue;
                vs[x][y] = 1;
                bool tmp = (s[x][y] == 'F');
                q[tmp].emplace(x, y);
            }
        }
        ++cnt;
        cur ^= 1;
    }
    cout << cnt;
    return 0;
}

Compilation message (stderr)

tracks.cpp: In function 'int main()':
tracks.cpp:24:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   24 |             auto [u, v] = q[cur].front(); q[cur].pop();
      |                  ^

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