oj.uz

Submission #1015783

# Submission time Handle Problem Language Result Execution time Memory
1015783 2024-07-06T19:02:29 Z KALARRY Tracks in the Snow (BOI13_tracks) C++14
84.6875 / 100
 2000 ms 1048576 KB 
//chockolateman

#include<bits/stdc++.h>

using namespace std;

const int INF = 1e9;

int H,W,di[4] = {1,-1,0,0},dj[4] = {0,0,1,-1},dist[16000005];
char grid[4005][4005];
vector<pair<int,int>> adj[16000005];

int id(int i,int j)
{
    return (i-1)*W + j;
}

bool is_ok(int i,int j)
{
    if(i >= 1 && i <= H && j >= 1 && j <= W && grid[i][j] != '.')
        return true;
    return false;
}

void connect_neighs()
{
    for(int i = 1 ; i <= H ; i++)
        for(int j = 1 ; j <= W ; j++)
        {
            if(grid[i][j]=='.')
                continue;
            for(int k = 0 ; k <= 3 ; k++)
            {
                int new_i = i + di[k];
                int new_j = j + dj[k];
                if(is_ok(new_i,new_j))
                {
                    if(grid[i][j]==grid[new_i][new_j])
                        adj[id(i,j)].push_back({id(new_i,new_j),0});
                    else
                        adj[id(i,j)].push_back({id(new_i,new_j),1});
                }
            }
        }
}

void BFS(int start)
{
    for(int i = 1 ; i <= H ; i++)
        for(int j = 1 ; j <= W ; j++)
            if(grid[i][j]!='.')
                dist[id(i,j)] = INF;
    deque<int> q;
    dist[start] = 0;
    if(grid[1][1]!='.')
        dist[start] = 1;
    q.push_back(start);
    while(!q.empty())
    {
        int v = q.front();
        q.pop_front();
        for(auto e : adj[v])
        {
            int u = e.first;
            int w = e.second;
            if(dist[v] + w < dist[u])
            {
                dist[u] = dist[v] + w;
                if(w==0)
                    q.push_front(u);
                else
                    q.push_back(u);
            }
        }
    }
}

int main()
{
    scanf("%d%d",&H,&W);
    for(int i = 1 ; i <= H ; i++)
        for(int j = 1 ; j <= W ; j++)
            scanf(" %c",&grid[i][j]);
    connect_neighs();
    BFS(id(1,1));
    int ans = 0;
    for(int i = 1 ; i <= H ; i++)
        for(int j = 1 ; j <= W ; j++)
            ans = max(ans,dist[(id(i,j))]);
    printf("%d\n",ans);
    return 0;
}

Compilation message

tracks.cpp: In function 'int main()':
tracks.cpp:80:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   80 |     scanf("%d%d",&H,&W);
      |     ~~~~~^~~~~~~~~~~~~~
tracks.cpp:83:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   83 |             scanf(" %c",&grid[i][j]);
      |             ~~~~~^~~~~~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 182 ms 390040 KB Output is correct
2 Correct 134 ms 376148 KB Output is correct
3 Correct 148 ms 376184 KB Output is correct
4 Correct 159 ms 385964 KB Output is correct
5 Correct 139 ms 378452 KB Output is correct
6 Correct 134 ms 376148 KB Output is correct
7 Correct 135 ms 376380 KB Output is correct
8 Correct 131 ms 376404 KB Output is correct
9 Correct 143 ms 376676 KB Output is correct
10 Correct 181 ms 378448 KB Output is correct
11 Correct 135 ms 378964 KB Output is correct
12 Correct 147 ms 381524 KB Output is correct
13 Correct 149 ms 378448 KB Output is correct
14 Correct 145 ms 378448 KB Output is correct
15 Correct 172 ms 387668 KB Output is correct
16 Correct 177 ms 390224 KB Output is correct
17 Correct 172 ms 383572 KB Output is correct
18 Correct 169 ms 386132 KB Output is correct

Subtask #2
54.6875 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 170 ms 391780 KB Output is correct
2 Correct 369 ms 417028 KB Output is correct
3 Correct 1057 ms 602048 KB Output is correct
4 Correct 404 ms 422224 KB Output is correct
5 Correct 732 ms 561128 KB Output is correct
6 Runtime error 1766 ms 1048576 KB Execution killed with signal 9
7 Correct 150 ms 392332 KB Output is correct
8 Correct 150 ms 391760 KB Output is correct
9 Correct 154 ms 377684 KB Output is correct
10 Correct 143 ms 376568 KB Output is correct
11 Correct 149 ms 392020 KB Output is correct
12 Correct 143 ms 377172 KB Output is correct
13 Correct 291 ms 416852 KB Output is correct
14 Correct 211 ms 400616 KB Output is correct
15 Correct 191 ms 393808 KB Output is correct
16 Correct 211 ms 396372 KB Output is correct
17 Correct 539 ms 473932 KB Output is correct
18 Correct 386 ms 438100 KB Output is correct
19 Correct 391 ms 422292 KB Output is correct
20 Correct 341 ms 434644 KB Output is correct
21 Correct 638 ms 517180 KB Output is correct
22 Correct 783 ms 561236 KB Output is correct
23 Correct 832 ms 559416 KB Output is correct
24 Correct 664 ms 511316 KB Output is correct
25 Correct 1091 ms 612692 KB Output is correct
26 Correct 1551 ms 1048576 KB Output is correct
27 Runtime error 1600 ms 1048576 KB Execution killed with signal 9
28 Runtime error 1608 ms 1048576 KB Execution killed with signal 9
29 Runtime error 1610 ms 1048576 KB Execution killed with signal 9
30 Runtime error 1671 ms 1048576 KB Execution killed with signal 9
31 Execution timed out 2044 ms 918164 KB Time limit exceeded
32 Runtime error 1601 ms 1048576 KB Execution killed with signal 9