oj.uz

Submission #1043878

# Submission time Handle Problem Language Result Execution time Memory
1043878 2024-08-05T02:41:48 Z daviedu Tracks in the Snow (BOI13_tracks) C++17
100 / 100
 556 ms 88908 KB 
#include <bits/stdc++.h>
using namespace std;

#define fastio ios_base::sync_with_stdio(0); cin.tie(0)
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define ll long long

struct P{
    ll x, y;
};

void dbg_out() { cerr << endl; }
template <typename H, typename... T>
void dbg_out(H h, T... t) { cerr << ' ' << h; dbg_out(t...); }
#define dbg(...) { cerr << #__VA_ARGS__ << ':'; dbg_out(__VA_ARGS__); }


const int N = 4001;
char grid[N][N];
int dist[N][N];
int h, w;

int valid(int x, int y){
    return (0 <= x && x < h) && (0 <= y && y < w);
}

int dx[] = {1, -1, 0, 0};
int dy[] = {0, 0, 1, -1};

signed main(){
    fastio;
    cin >> h >> w;
    for (int i=0; i<h; i++){
        for (int j=0; j<w; j++){
            cin >> grid[i][j];
        }
    }

    memset(dist, -1, sizeof(dist));
    int ans=1;
    queue<pair<int, int>> q0, q1;
    dist[0][0] = 1;
    q0.push({0, 0});
    int x, y;
    int ctr=0;
    while (!q0.empty() || !q1.empty()){
        while (!q0.empty()){
            tie(x, y) = q0.front(); q0.pop();
            ans = max(ans, dist[x][y]);
            for (int i=0; i<4; i++){
                int a, b;
                a = dx[i]+x;
                b = dy[i]+y;
                if (!valid(a, b) || grid[a][b] == '.' || dist[a][b] != -1) continue;
                dist[a][b] = dist[x][y];
                if (grid[a][b] != grid[x][y]){
                    dist[a][b]++;
                    q1.push({a, b});
                }
                else q0.push({a, b});
            }
        }
        swap(q0, q1);
    }

    cout << ans << '\n';
}

Compilation message

tracks.cpp: In function 'int main()':
tracks.cpp:46:9: warning: unused variable 'ctr' [-Wunused-variable]
   46 |     int ctr=0;
      |         ^~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 66140 KB Output is correct
2 Correct 6 ms 64092 KB Output is correct
3 Correct 9 ms 64204 KB Output is correct
4 Correct 10 ms 66396 KB Output is correct
5 Correct 8 ms 64212 KB Output is correct
6 Correct 7 ms 64092 KB Output is correct
7 Correct 8 ms 64164 KB Output is correct
8 Correct 7 ms 64156 KB Output is correct
9 Correct 7 ms 64228 KB Output is correct
10 Correct 9 ms 64248 KB Output is correct
11 Correct 8 ms 64092 KB Output is correct
12 Correct 9 ms 64212 KB Output is correct
13 Correct 9 ms 64088 KB Output is correct
14 Correct 9 ms 64204 KB Output is correct
15 Correct 15 ms 66196 KB Output is correct
16 Correct 15 ms 66136 KB Output is correct
17 Correct 13 ms 66320 KB Output is correct
18 Correct 13 ms 66392 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 78496 KB Output is correct
2 Correct 38 ms 68244 KB Output is correct
3 Correct 205 ms 78544 KB Output is correct
4 Correct 57 ms 72276 KB Output is correct
5 Correct 150 ms 76368 KB Output is correct
6 Correct 533 ms 88908 KB Output is correct
7 Correct 10 ms 78772 KB Output is correct
8 Correct 11 ms 78556 KB Output is correct
9 Correct 9 ms 64088 KB Output is correct
10 Correct 7 ms 64092 KB Output is correct
11 Correct 9 ms 78560 KB Output is correct
12 Correct 8 ms 64092 KB Output is correct
13 Correct 38 ms 68320 KB Output is correct
14 Correct 25 ms 68188 KB Output is correct
15 Correct 21 ms 68188 KB Output is correct
16 Correct 21 ms 66324 KB Output is correct
17 Correct 93 ms 72392 KB Output is correct
18 Correct 63 ms 72272 KB Output is correct
19 Correct 58 ms 72280 KB Output is correct
20 Correct 51 ms 70232 KB Output is correct
21 Correct 122 ms 76368 KB Output is correct
22 Correct 148 ms 76368 KB Output is correct
23 Correct 163 ms 74452 KB Output is correct
24 Correct 121 ms 76628 KB Output is correct
25 Correct 241 ms 78676 KB Output is correct
26 Correct 246 ms 78416 KB Output is correct
27 Correct 389 ms 80468 KB Output is correct
28 Correct 556 ms 88884 KB Output is correct
29 Correct 510 ms 87244 KB Output is correct
30 Correct 491 ms 86244 KB Output is correct
31 Correct 384 ms 76984 KB Output is correct
32 Correct 323 ms 79400 KB Output is correct