oj.uz

Submission #799000

# Submission time Handle Problem Language Result Execution time Memory
799000 2023-07-31T08:34:07 Z dvtd Tracks in the Snow (BOI13_tracks) C++14
100 / 100
 870 ms 254172 KB 
// 

#include <bits/stdc++.h>

using namespace std;

typedef pair<int, int> ii;
typedef pair<int, ii> iii;
typedef long long ll;
typedef long double ld;

const ll infLL = 2e18 + 7;
const int inf = 2e9 + 7;
const int maxN = 4010;
const ll MOD = 998244353;
const double eps = 1e-12;

int d[maxN][maxN];
int a[maxN][maxN];
bool visited[maxN][maxN];
int dx[4] = {-1, 1, 0, 0};
int dy[4] = {0, 0, -1, 1};
int res = 0;

bool check(int x, int y, int n, int m)
{
    return (0 <= x && x < n && 0 <= y && y < m);
}

void bfs(int n, int m)
{
    deque<ii> q; q.push_front(ii(0, 0));

    while (!q.empty())
    {
        int ux = q.front().first;
        int uy = q.front().second;
        q.pop_front();

        if (visited[ux][uy]) continue;
        visited[ux][uy] = true;

        res = max(res, d[ux][uy]);

        for (int k = 0; k < 4; ++k)
        {
            int vx = ux + dx[k];
            int vy = uy + dy[k];
            if (!check(vx, vy, n, m) || visited[vx][vy] || a[vx][vy] == 0) continue;

            if (a[vx][vy] == a[ux][uy])
            {
                d[vx][vy] = d[ux][uy];
                q.push_front(ii(vx, vy));
            }
            else 
            {
                d[vx][vy] = d[ux][uy] + 1;
                q.push_back(ii(vx, vy));
            }
        }
    }
}

void solve()
{
    memset(visited, false, sizeof visited);
    memset(d, 0, sizeof d);
    memset(a, 0, sizeof a);

    int n, m; cin >> n >> m;
    for (int i = 0; i < n; ++i)
    {
        for (int j = 0; j < m; ++j)
        {
            char c; cin >> c;
            if (c == 'F') a[i][j] = 1;
            else if (c == 'R') a[i][j] = 2;
            else a[i][j] = 0;
        }
    }

    bfs(n, m);

    cout << res + 1 << '\n';
}

void setIO(string name)
{
    ios_base::sync_with_stdio(0);
    cin.tie(NULL); cout.tie(NULL);
    if (!name.size()) return;

    #ifndef ONLINE_JUDGE
        freopen((name + ".inp").c_str(), "r", stdin);
        freopen((name + ".out").c_str(), "w", stdout);
    #endif
}

int main()
{
    setIO("");
    int test = 1; //cin >> test;
    while (test--) solve();
}

//         _       _      _
//        | |     | |    | |
//      __| |_   _| |_ __| |
//     / _` \ \ / / __/ _` |
//    | (_| |\ V /| || (_| |
//     \__,_| \_/  \__\__,_|
//
//

Compilation message

tracks.cpp: In function 'void setIO(std::string)':
tracks.cpp:95:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   95 |         freopen((name + ".inp").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tracks.cpp:96:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   96 |         freopen((name + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 69 ms 142140 KB Output is correct
2 Correct 46 ms 141872 KB Output is correct
3 Correct 46 ms 141912 KB Output is correct
4 Correct 53 ms 142372 KB Output is correct
5 Correct 49 ms 141912 KB Output is correct
6 Correct 45 ms 141812 KB Output is correct
7 Correct 45 ms 141904 KB Output is correct
8 Correct 46 ms 141860 KB Output is correct
9 Correct 46 ms 141924 KB Output is correct
10 Correct 47 ms 141896 KB Output is correct
11 Correct 48 ms 142020 KB Output is correct
12 Correct 52 ms 141988 KB Output is correct
13 Correct 47 ms 141916 KB Output is correct
14 Correct 48 ms 141900 KB Output is correct
15 Correct 58 ms 142128 KB Output is correct
16 Correct 61 ms 142180 KB Output is correct
17 Correct 56 ms 142140 KB Output is correct
18 Correct 53 ms 142412 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 47 ms 141924 KB Output is correct
2 Correct 97 ms 143436 KB Output is correct
3 Correct 364 ms 157552 KB Output is correct
4 Correct 150 ms 145488 KB Output is correct
5 Correct 181 ms 150676 KB Output is correct
6 Correct 870 ms 182464 KB Output is correct
7 Correct 53 ms 141924 KB Output is correct
8 Correct 56 ms 141856 KB Output is correct
9 Correct 49 ms 141900 KB Output is correct
10 Correct 48 ms 141896 KB Output is correct
11 Correct 47 ms 141944 KB Output is correct
12 Correct 46 ms 141804 KB Output is correct
13 Correct 98 ms 143396 KB Output is correct
14 Correct 74 ms 142880 KB Output is correct
15 Correct 70 ms 142796 KB Output is correct
16 Correct 72 ms 142552 KB Output is correct
17 Correct 179 ms 145916 KB Output is correct
18 Correct 142 ms 145812 KB Output is correct
19 Correct 128 ms 145468 KB Output is correct
20 Correct 114 ms 145308 KB Output is correct
21 Correct 245 ms 150984 KB Output is correct
22 Correct 178 ms 150652 KB Output is correct
23 Correct 297 ms 149536 KB Output is correct
24 Correct 212 ms 150788 KB Output is correct
25 Correct 591 ms 157504 KB Output is correct
26 Correct 570 ms 254172 KB Output is correct
27 Correct 703 ms 183688 KB Output is correct
28 Correct 854 ms 182464 KB Output is correct
29 Correct 845 ms 178644 KB Output is correct
30 Correct 801 ms 186720 KB Output is correct
31 Correct 709 ms 152856 KB Output is correct
32 Correct 609 ms 187928 KB Output is correct