Submission #391413

# Submission time Handle Problem Language Result Execution time Memory
391413 2021-04-18T17:22:44 Z ml1234 Mecho (IOI09_mecho) C++17
5 / 100
75 ms 6328 KB
#include <iostream>
#include <string>
#include <queue>
using namespace std;
bool validmecho(int i, int j);
bool validbees(int i, int j);
bool bfs(int starttime);

string grid[800];
int bees[800][800];
int dx[] = {0, -1, 1, 0}, dy[] = {-1, 0, 0, 1};
int n, s;
pair<int, int> mecho;
int main() 
{
    cin >> n >> s;
    for (int i = 0; i < n; i++)
    {
        cin >> grid[i];
        for (int j = 0; j < n; j++)
        {
            if (grid[i][j] == 'M')
            {
                mecho = {i, j};
            }
        }
    }
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            bees[i][j] = 1e9;
        }
    }
    queue<pair<int, int>> q;
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            if (grid[i][j] == 'H')
            {
                q.push({i, j});
                bees[i][j] = 0;
            }
        }
    }
    while (!q.empty())
    {
        int curri = q.front().first, currj = q.front().second;
        q.pop();
        for (int d = 0; d < 4; d++)
        {
            int nexti = curri + dx[d], nextj = currj + dy[d];
            if (validbees(nexti, nextj) && bees[nexti][nextj] > bees[curri][currj] + s)
            {
                bees[nexti][nextj] = bees[curri][currj] + s;
                q.push({nexti, nextj});
            }
        }
    }
    int low = 0, high = n * n;
    while (low < high)
    {
        int mid = (low + high + 1) / 2;
        if (bfs(mid))
        {
            low = mid;
        }
        else
        {
            high = mid - 1;
        }
    }
    cout << low << endl;
    return 0;
}

bool ongrid(int i, int j)
{
    return (i >= 0 && i < n && j >= 0 && j < n);
}
bool validbees(int i, int j)
{
    return (ongrid(i, j) && !(grid[i][j] == 'T') && !(grid[i][j] == 'D') && !(grid[i][j] == 'H'));
}
bool validmecho(int i, int j)
{
    return (ongrid(i, j) && !(grid[i][j] == 'T'));
}

bool bfs(int starttime)
{
    if (starttime * s <= bees[mecho.first][mecho.second])
    {
        return false;
    }
    queue<pair<int, int>> q;
    q.push(mecho);
    vector<vector<int>> mechodist(n, vector<int> (n, -1));
    mechodist[mecho.first][mecho.second] = starttime * s;
    while (!q.empty())
    {
        int curri = q.front().first, currj = q.front().second;
        q.pop();
        if (grid[curri][currj] == 'D')
        {
            return true;
        }
        for (int d = 0; d < 4; d++)
        {
            int nexti = curri + dx[d], nextj = currj + dy[d];
            if (!validmecho(nexti, nextj))
            {
                continue;
            }
            if (mechodist[nexti][nextj] == -1)
            {
                if (bees[nexti][nextj] > mechodist[curri][currj] + 1)
                {
                    mechodist[nexti][nextj] = mechodist[curri][currj] + 1;
                    q.push({nexti, nextj});
                }
            }
        }
    }
    return false;
}
# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 332 KB Output isn't correct
2 Incorrect 1 ms 332 KB Output isn't correct
3 Incorrect 1 ms 332 KB Output isn't correct
4 Incorrect 1 ms 332 KB Output isn't correct
5 Correct 1 ms 332 KB Output is correct
6 Incorrect 1 ms 332 KB Output isn't correct
7 Incorrect 54 ms 6272 KB Output isn't correct
8 Incorrect 1 ms 332 KB Output isn't correct
9 Incorrect 1 ms 332 KB Output isn't correct
10 Incorrect 1 ms 332 KB Output isn't correct
11 Incorrect 1 ms 332 KB Output isn't correct
12 Incorrect 1 ms 460 KB Output isn't correct
13 Correct 1 ms 460 KB Output is correct
14 Incorrect 1 ms 460 KB Output isn't correct
15 Incorrect 1 ms 332 KB Output isn't correct
16 Incorrect 1 ms 332 KB Output isn't correct
17 Incorrect 1 ms 332 KB Output isn't correct
18 Incorrect 1 ms 328 KB Output isn't correct
19 Incorrect 1 ms 360 KB Output isn't correct
20 Incorrect 1 ms 332 KB Output isn't correct
21 Incorrect 1 ms 460 KB Output isn't correct
22 Incorrect 1 ms 456 KB Output isn't correct
23 Incorrect 1 ms 460 KB Output isn't correct
24 Incorrect 1 ms 460 KB Output isn't correct
25 Incorrect 1 ms 460 KB Output isn't correct
26 Incorrect 1 ms 460 KB Output isn't correct
27 Incorrect 1 ms 460 KB Output isn't correct
28 Incorrect 1 ms 460 KB Output isn't correct
29 Incorrect 1 ms 460 KB Output isn't correct
30 Incorrect 1 ms 460 KB Output isn't correct
31 Incorrect 1 ms 588 KB Output isn't correct
32 Incorrect 1 ms 588 KB Output isn't correct
33 Incorrect 7 ms 2124 KB Output isn't correct
34 Incorrect 7 ms 2132 KB Output isn't correct
35 Incorrect 9 ms 2136 KB Output isn't correct
36 Incorrect 8 ms 2380 KB Output isn't correct
37 Incorrect 9 ms 2380 KB Output isn't correct
38 Incorrect 15 ms 2468 KB Output isn't correct
39 Incorrect 10 ms 2764 KB Output isn't correct
40 Incorrect 10 ms 2828 KB Output isn't correct
41 Incorrect 15 ms 2876 KB Output isn't correct
42 Incorrect 13 ms 3436 KB Output isn't correct
43 Incorrect 12 ms 3432 KB Output isn't correct
44 Incorrect 18 ms 3468 KB Output isn't correct
45 Incorrect 15 ms 3848 KB Output isn't correct
46 Incorrect 15 ms 3844 KB Output isn't correct
47 Incorrect 24 ms 3916 KB Output isn't correct
48 Incorrect 17 ms 4304 KB Output isn't correct
49 Incorrect 17 ms 4300 KB Output isn't correct
50 Incorrect 32 ms 4332 KB Output isn't correct
51 Incorrect 20 ms 4676 KB Output isn't correct
52 Incorrect 21 ms 4744 KB Output isn't correct
53 Incorrect 37 ms 4756 KB Output isn't correct
54 Incorrect 23 ms 5216 KB Output isn't correct
55 Incorrect 23 ms 5204 KB Output isn't correct
56 Incorrect 46 ms 5268 KB Output isn't correct
57 Incorrect 26 ms 5708 KB Output isn't correct
58 Incorrect 26 ms 5708 KB Output isn't correct
59 Incorrect 54 ms 5732 KB Output isn't correct
60 Incorrect 30 ms 6212 KB Output isn't correct
61 Incorrect 30 ms 6212 KB Output isn't correct
62 Incorrect 60 ms 6240 KB Output isn't correct
63 Correct 48 ms 6224 KB Output is correct
64 Incorrect 56 ms 6232 KB Output isn't correct
65 Incorrect 49 ms 6240 KB Output isn't correct
66 Incorrect 51 ms 6248 KB Output isn't correct
67 Incorrect 48 ms 6244 KB Output isn't correct
68 Correct 55 ms 6288 KB Output is correct
69 Incorrect 58 ms 6264 KB Output isn't correct
70 Incorrect 66 ms 6260 KB Output isn't correct
71 Incorrect 56 ms 6272 KB Output isn't correct
72 Incorrect 61 ms 6256 KB Output isn't correct
73 Incorrect 62 ms 6300 KB Output isn't correct
74 Incorrect 75 ms 6268 KB Output isn't correct
75 Incorrect 72 ms 6288 KB Output isn't correct
76 Incorrect 55 ms 6260 KB Output isn't correct
77 Incorrect 65 ms 6288 KB Output isn't correct
78 Incorrect 66 ms 6268 KB Output isn't correct
79 Incorrect 55 ms 6296 KB Output isn't correct
80 Incorrect 54 ms 6268 KB Output isn't correct
81 Incorrect 54 ms 6316 KB Output isn't correct
82 Incorrect 55 ms 6304 KB Output isn't correct
83 Correct 55 ms 6276 KB Output is correct
84 Incorrect 55 ms 6328 KB Output isn't correct
85 Incorrect 57 ms 6276 KB Output isn't correct
86 Incorrect 67 ms 6320 KB Output isn't correct
87 Incorrect 54 ms 6308 KB Output isn't correct
88 Correct 55 ms 6256 KB Output is correct
89 Incorrect 54 ms 6292 KB Output isn't correct
90 Incorrect 65 ms 6272 KB Output isn't correct
91 Incorrect 66 ms 6264 KB Output isn't correct
92 Incorrect 55 ms 6260 KB Output isn't correct