oj.uz

Submission #868006

# Submission time Handle Problem Language Result Execution time Memory
868006 2023-10-30T07:45:35 Z theghostking Tracks in the Snow (BOI13_tracks) C++17
100 / 100
 1403 ms 333384 KB 
#include <bits/stdc++.h>
using namespace std;

#define int long long

int h,w;

int hsh(int i, int j){
    // 0 <= i < h
    // 0 <= j < w
    return (i*w)+j;
}

pair<int,int> unhsh(int x){
    return {x/w,x%w};
}

signed main() {
    cin >> h >> w;
    int grid[h][w];
    bool visited[h][w];
    for (int i = 0; i<h; i++){
        for (int j = 0; j<w; j++){
            char a;
            cin >> a;
            if (a == '.') grid[i][j] = 0;
            if (a == 'R') grid[i][j] = 1;
            if (a == 'F') grid[i][j] = 2;
            visited[i][j] = false;
        }
    }

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

    int mxn = hsh(h-1,w-1);
    vector<int> dist(mxn+1, 1e9);
    deque<pair<int,int>> q;
    q.push_front({0,0});
    dist[0] = 1;
    int ans = 0;
    while (!q.empty()){
        pair<int,int> v = q.front();
        int vhsh = hsh(v.first,v.second);
        q.pop_front();
        ans = max(ans,dist[vhsh]);
        if (visited[v.first][v.second]) continue;
        visited[v.first][v.second] = true;
        int r = v.first;
        int c = v.second;
        for (int k = 0; k<4; k++){
            int rr = r + dx[k];
            int cc = c + dy[k];
            if (rr < 0 || rr >= h || cc < 0 || cc >= w) continue;
            if (visited[rr][cc]) continue;
            if (grid[rr][cc] == 0) continue;
            int khsh = hsh(rr,cc);
            if (dist[vhsh] + (grid[r][c] != grid[rr][cc]) < dist[khsh]){
                dist[khsh] = dist[vhsh] + (grid[r][c] != grid[rr][cc]);
                if (grid[rr][cc] != grid[r][c]){
                    q.push_back({rr,cc});
                }
                else{
                    q.push_front({rr,cc});
                }
            }
        }
    }
    cout << ans;
    return 0;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 4696 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 11 ms 3424 KB Output is correct
5 Correct 5 ms 1884 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 504 KB Output is correct
8 Correct 1 ms 348 KB Output is correct
9 Correct 1 ms 448 KB Output is correct
10 Correct 4 ms 1372 KB Output is correct
11 Correct 3 ms 1216 KB Output is correct
12 Correct 8 ms 1884 KB Output is correct
13 Correct 5 ms 1884 KB Output is correct
14 Correct 5 ms 1884 KB Output is correct
15 Correct 18 ms 4700 KB Output is correct
16 Correct 21 ms 4700 KB Output is correct
17 Correct 16 ms 4440 KB Output is correct
18 Correct 12 ms 3420 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 1116 KB Output is correct
2 Correct 92 ms 27860 KB Output is correct
3 Correct 780 ms 281960 KB Output is correct
4 Correct 198 ms 66216 KB Output is correct
5 Correct 422 ms 159208 KB Output is correct
6 Correct 1403 ms 310932 KB Output is correct
7 Correct 3 ms 1116 KB Output is correct
8 Correct 3 ms 1116 KB Output is correct
9 Correct 4 ms 1372 KB Output is correct
10 Correct 2 ms 860 KB Output is correct
11 Correct 3 ms 1116 KB Output is correct
12 Correct 1 ms 604 KB Output is correct
13 Correct 93 ms 27856 KB Output is correct
14 Correct 54 ms 16312 KB Output is correct
15 Correct 55 ms 18012 KB Output is correct
16 Correct 44 ms 11604 KB Output is correct
17 Correct 240 ms 71764 KB Output is correct
18 Correct 231 ms 70744 KB Output is correct
19 Correct 202 ms 66388 KB Output is correct
20 Correct 169 ms 60776 KB Output is correct
21 Correct 441 ms 164184 KB Output is correct
22 Correct 412 ms 158748 KB Output is correct
23 Correct 468 ms 136692 KB Output is correct
24 Correct 430 ms 160520 KB Output is correct
25 Correct 1083 ms 282324 KB Output is correct
26 Correct 1285 ms 316424 KB Output is correct
27 Correct 1238 ms 333384 KB Output is correct
28 Correct 1319 ms 311000 KB Output is correct
29 Correct 1336 ms 305624 KB Output is correct
30 Correct 1286 ms 313772 KB Output is correct
31 Correct 882 ms 181844 KB Output is correct
32 Correct 1272 ms 330840 KB Output is correct