oj.uz

Submission #757361

# Submission time Handle Problem Language Result Execution time Memory
757361 2023-06-13T06:12:20 Z dxz05 Tracks in the Snow (BOI13_tracks) C++17
100 / 100
 1079 ms 42024 KB 
#pragma GCC optimize("Ofast,O3,unroll-loops")
#pragma GCC target("avx2")

#include <bits/stdc++.h>

using namespace std;

#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define bpc(x) __builtin_popcount(x)
#define bpcll(x) __builtin_popcountll(x)
#define MP make_pair
//#define endl '\n'

mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

typedef long long ll;
const int MOD = 1e9 + 7;
const int N = 4004;

char a[N][N];
bool used[N][N];

void solve(){
    int n, m;
    cin >> n >> m;

    int animals_cnt = 0;
    for (int i = 0; i < n; i++){
        for (int j = 0; j < m; j++){
            cin >> a[i][j];
            animals_cnt += a[i][j] == 'F' || a[i][j] == 'R';
        }
    }

    char animal = a[0][0];

    if (animal == '.'){
        cout << 0 << endl;
        return;
    }

    vector<int> dx = {0, 1, 0, -1};
    vector<int> dy = {1, 0, -1, 0};

    int ans = 0;

    queue<pair<int, int>> q;
    q.emplace(0, 0);
    used[0][0] = true;

    queue<pair<int, int>> _q;

    while (animals_cnt){
        ans++;

        while (!q.empty()){
            auto [x, y] = q.front();
            q.pop();

            if (a[x][y] == animal) animals_cnt--;
            a[x][y] = '?';

            for (int it = 0; it < 4; it++){
                int i = x + dx[it];
                int j = y + dy[it];

                if (i >= 0 && i < n && j >= 0 && j < m && !used[i][j]){
                    if (a[i][j] == '?' || a[i][j] == animal){
                        q.emplace(i, j);
                    } else if (a[i][j] != '.'){
                        _q.emplace(i, j);
                    }
                    used[i][j] = true;
                }

            }

        }

        q.swap(_q);

        animal ^= 'F' ^ 'R';
    }

    cout << ans << endl;

}

int main(){
    clock_t startTime = clock();
    ios_base::sync_with_stdio(false);

#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif

    int test_cases = 1;
//    cin >> test_cases;

    for (int test = 1; test <= test_cases; test++){
        // cout << (solve() ? "YES" : "NO") << endl;
        solve();
    }

#ifdef LOCAL
    cerr << "Time: " << int((double) (clock() - startTime) / CLOCKS_PER_SEC * 1000) << " ms" << endl;
#endif

    return 0;
}

Compilation message

tracks.cpp: In function 'int main()':
tracks.cpp:91:13: warning: unused variable 'startTime' [-Wunused-variable]
   91 |     clock_t startTime = clock();
      |             ^~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 4180 KB Output is correct
2 Correct 1 ms 468 KB Output is correct
3 Correct 1 ms 724 KB Output is correct
4 Correct 10 ms 4308 KB Output is correct
5 Correct 4 ms 2516 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 1 ms 724 KB Output is correct
8 Correct 1 ms 724 KB Output is correct
9 Correct 1 ms 1108 KB Output is correct
10 Correct 4 ms 2296 KB Output is correct
11 Correct 4 ms 1876 KB Output is correct
12 Correct 7 ms 2612 KB Output is correct
13 Correct 4 ms 2516 KB Output is correct
14 Correct 5 ms 2564 KB Output is correct
15 Correct 15 ms 4280 KB Output is correct
16 Correct 16 ms 4236 KB Output is correct
17 Correct 12 ms 4088 KB Output is correct
18 Correct 10 ms 4332 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 30200 KB Output is correct
2 Correct 68 ms 10072 KB Output is correct
3 Correct 420 ms 31728 KB Output is correct
4 Correct 108 ms 15096 KB Output is correct
5 Correct 287 ms 23716 KB Output is correct
6 Correct 1068 ms 41824 KB Output is correct
7 Correct 16 ms 31620 KB Output is correct
8 Correct 17 ms 30180 KB Output is correct
9 Correct 3 ms 468 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 16 ms 30988 KB Output is correct
12 Correct 2 ms 1492 KB Output is correct
13 Correct 80 ms 10132 KB Output is correct
14 Correct 42 ms 7472 KB Output is correct
15 Correct 31 ms 8048 KB Output is correct
16 Correct 30 ms 3484 KB Output is correct
17 Correct 173 ms 16128 KB Output is correct
18 Correct 111 ms 15976 KB Output is correct
19 Correct 106 ms 15084 KB Output is correct
20 Correct 94 ms 14060 KB Output is correct
21 Correct 246 ms 24512 KB Output is correct
22 Correct 320 ms 23828 KB Output is correct
23 Correct 326 ms 19964 KB Output is correct
24 Correct 271 ms 24636 KB Output is correct
25 Correct 452 ms 31660 KB Output is correct
26 Correct 500 ms 27824 KB Output is correct
27 Correct 840 ms 33464 KB Output is correct
28 Correct 1079 ms 42024 KB Output is correct
29 Correct 1018 ms 40428 KB Output is correct
30 Correct 926 ms 39100 KB Output is correct
31 Correct 724 ms 25852 KB Output is correct
32 Correct 707 ms 32444 KB Output is correct