Submission #1109313

#	Time	Username	Problem	Language	Result	Execution time	Memory
1109313		Kirill22	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	1129 ms	297824 KiB

tracks

#include "bits/stdc++.h"
 
using namespace std;
 
vector<pair<int, int>> d{{0, -1}, {0, 1}, {1, 0}, {-1, 0}};
 
void solve() {
    int n, m;
    cin >> n >> m;
    vector<string> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    auto check = [&] (int x, int y) {
        return x >= 0 && x < n && y >= 0 && y < m;
    };
    char c = a[0][0];
    vector<pair<int, int>> ts;
    vector<vector<int>> usd(n, vector<int> (m));
    auto dfs = [&] (int x, int y) {
        vector<pair<int, int>> qu = {{x, y}};
        usd[x][y] = 1;
        for (int i = 0; i < (int) qu.size(); i++) {
            auto [x, y] = qu[i];
            ts.push_back({x, y});
            for (auto [x2, y2] : d) {
                x2 += x, y2 += y;
                if (check(x2, y2) && a[x2][y2] == c && !usd[x2][y2]) {
                    usd[x2][y2] = 1;
                    qu.push_back({x2, y2});
                }
            }
        }
    };
    dfs(0, 0);
    int ans = 0;
    while (1) {
        c = c == 'F' ? 'R' : 'F';
        ans++;
        auto ct = ts;
        ts.clear();
        for (auto [x, y] : ct) {
            for (auto [x2, y2] : d) {
                x2 += x, y2 += y;
                if (check(x2, y2) && a[x2][y2] == c && !usd[x2][y2]) {
                    dfs(x2, y2);
                }
            }
        }
        if (ts.empty()) {
            break;
        }
    }
    cout << ans << '\n';
}
 
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int t = 1;
//    cin >> t;
    while (t--) {
        solve();
    }
}

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