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Submission #997021

# Submission time Handle Problem Language Result Execution time Memory
997021 2024-06-11T15:26:54 Z imann Mecho (IOI09_mecho) C++17
100 / 100
 137 ms 6920 KB 
#include <iostream>
#include <array>
#include <string>
#include <queue>

const int MAX_N = 800 + 1;
const int INF = 1e9;

std::array<std::string, MAX_N> grid;
std::array<std::array<int, MAX_N>, MAX_N> minuteToBeHive, level;

void bfs(int n) {
    std::queue<std::pair<int, int>> q;
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            minuteToBeHive[i][j] = INF;
            if (grid[i][j] == 'H') {
                q.push({i, j});
                minuteToBeHive[i][j] = 0;
            }
        }
    }

    while (!q.empty()) {
        auto v = q.front();
        q.pop();
        if (v.first > 0) {
            if (grid[v.first - 1][v.second] == 'G' || grid[v.first - 1][v.second] == 'M') {
                if (minuteToBeHive[v.first - 1][v.second] == INF)
                    q.push({v.first - 1, v.second});
                minuteToBeHive[v.first - 1][v.second] = std::min(minuteToBeHive[v.first - 1][v.second], minuteToBeHive[v.first][v.second] + 1);
            }
        }
        if (v.first < n - 1) {
            if (grid[v.first + 1][v.second] == 'G' || grid[v.first + 1][v.second] == 'M') {
                if (minuteToBeHive[v.first + 1][v.second] == INF)
                    q.push({v.first + 1, v.second});
                minuteToBeHive[v.first + 1][v.second] = std::min(minuteToBeHive[v.first + 1][v.second], minuteToBeHive[v.first][v.second] + 1);
            }
        }
        if (v.second > 0) {
            if (grid[v.first][v.second - 1] == 'G' || grid[v.first][v.second - 1] == 'M') {
                if (minuteToBeHive[v.first][v.second - 1] == INF)
                    q.push({v.first, v.second - 1});
                minuteToBeHive[v.first][v.second - 1] = std::min(minuteToBeHive[v.first][v.second - 1], minuteToBeHive[v.first][v.second] + 1);
            }
        }
        if (v.second < n - 1) {
            if (grid[v.first][v.second + 1] == 'G' || grid[v.first][v.second + 1] == 'M') {
                if (minuteToBeHive[v.first][v.second + 1] == INF)
                    q.push({v.first, v.second + 1});
                minuteToBeHive[v.first][v.second + 1] = std::min(minuteToBeHive[v.first][v.second + 1], minuteToBeHive[v.first][v.second] + 1);
            }
        }
    }
}

bool bfs2(int n, int s, int startMinute) {
    std::pair<int, int> start, end;
    std::queue<std::pair<int, int>> q;
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            level[i][j] = INF;
            if (grid[i][j] == 'M')
                start = {i, j};
            if (grid[i][j] == 'D')
                end = {i, j};
        }
    }
    q.push(start);
    level[start.first][start.second] = 0;
    if (startMinute >= minuteToBeHive[start.first][start.second])
        return false;
    while (!q.empty()) {
        auto v = q.front();
        q.pop();
        if (v.first > 0) {
            if ((grid[v.first - 1][v.second] == 'G' || grid[v.first - 1][v.second] == 'D' || grid[v.first - 1][v.second] == 'M') && (startMinute + (level[v.first][v.second] + 1) / s < minuteToBeHive[v.first - 1][v.second])) {
                if (level[v.first - 1][v.second] == INF)
                    q.push({v.first - 1, v.second});
                level[v.first - 1][v.second] = std::min(level[v.first - 1][v.second], level[v.first][v.second] + 1);
            }
        }
        if (v.first < n - 1) {
            if ((grid[v.first + 1][v.second] == 'G' || grid[v.first + 1][v.second] == 'D' || grid[v.first + 1][v.second] == 'M') && (startMinute + (level[v.first][v.second] + 1) / s < minuteToBeHive[v.first + 1][v.second])) {
                if (level[v.first + 1][v.second] == INF)
                    q.push({v.first + 1, v.second});
                level[v.first + 1][v.second] = std::min(level[v.first + 1][v.second], level[v.first][v.second] + 1);
            }
        }
        if (v.second > 0) {
            if ((grid[v.first][v.second - 1] == 'G' || grid[v.first][v.second - 1] == 'D' || grid[v.first][v.second - 1] == 'M') && (startMinute + (level[v.first][v.second] + 1) / s < minuteToBeHive[v.first][v.second - 1])) {
                if (level[v.first][v.second - 1] == INF)
                    q.push({v.first, v.second - 1});
                level[v.first][v.second - 1] = std::min(level[v.first][v.second - 1], level[v.first][v.second] + 1);
            }
        }
        if (v.second < n - 1) {
            if ((grid[v.first][v.second + 1] == 'G' || grid[v.first][v.second + 1] == 'D' || grid[v.first][v.second + 1] == 'M') && (startMinute + (level[v.first][v.second] + 1) / s < minuteToBeHive[v.first][v.second + 1])) {
                if (level[v.first][v.second + 1] == INF)
                    q.push({v.first, v.second + 1});
                level[v.first][v.second + 1] = std::min(level[v.first][v.second + 1], level[v.first][v.second] + 1);
            }
        }
    }
    return level[end.first][end.second] != INF;
}

int solve(int n, int s) {
    bfs(n);
    int l = 0, r = n * n;
    while (r - l > 1) {
        int mid = (r + l) / 2;
        if (bfs2(n, s, mid)) {
            l = mid;
        } else {
            r = mid;
        }
    }

    if (bfs2(n, s, l))
        return l;
    return -1;
}

int main() {
    int n, s; std::cin >> n >> s;
    for (int i = 0; i < n; ++i) {
        std::cin >> grid[i];
    }
    std::cout << solve(n, s) << std::endl;
}

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2520 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 0 ms 2396 KB Output is correct
4 Correct 1 ms 2396 KB Output is correct
5 Correct 0 ms 2396 KB Output is correct
6 Correct 0 ms 2516 KB Output is correct
7 Correct 73 ms 6392 KB Output is correct
8 Correct 1 ms 2396 KB Output is correct
9 Correct 1 ms 2396 KB Output is correct
10 Correct 1 ms 2396 KB Output is correct
11 Correct 1 ms 2396 KB Output is correct
12 Correct 1 ms 4700 KB Output is correct
13 Correct 1 ms 2652 KB Output is correct
14 Correct 1 ms 4700 KB Output is correct
15 Correct 1 ms 2396 KB Output is correct
16 Correct 0 ms 2396 KB Output is correct
17 Correct 1 ms 2516 KB Output is correct
18 Correct 1 ms 2396 KB Output is correct
19 Correct 0 ms 2396 KB Output is correct
20 Correct 0 ms 2396 KB Output is correct
21 Correct 1 ms 2652 KB Output is correct
22 Correct 1 ms 2652 KB Output is correct
23 Correct 1 ms 2652 KB Output is correct
24 Correct 0 ms 2652 KB Output is correct
25 Correct 1 ms 4700 KB Output is correct
26 Correct 1 ms 4700 KB Output is correct
27 Correct 1 ms 4700 KB Output is correct
28 Correct 1 ms 4700 KB Output is correct
29 Correct 1 ms 4700 KB Output is correct
30 Correct 1 ms 4700 KB Output is correct
31 Correct 1 ms 4700 KB Output is correct
32 Correct 1 ms 4700 KB Output is correct
33 Correct 7 ms 4956 KB Output is correct
34 Correct 5 ms 4956 KB Output is correct
35 Correct 17 ms 4956 KB Output is correct
36 Correct 7 ms 4952 KB Output is correct
37 Correct 11 ms 4976 KB Output is correct
38 Correct 21 ms 4956 KB Output is correct
39 Correct 8 ms 4956 KB Output is correct
40 Correct 9 ms 4956 KB Output is correct
41 Correct 28 ms 4956 KB Output is correct
42 Correct 11 ms 5208 KB Output is correct
43 Correct 10 ms 5212 KB Output is correct
44 Correct 35 ms 5212 KB Output is correct
45 Correct 14 ms 5468 KB Output is correct
46 Correct 13 ms 5248 KB Output is correct
47 Correct 40 ms 5480 KB Output is correct
48 Correct 15 ms 5468 KB Output is correct
49 Correct 15 ms 5656 KB Output is correct
50 Correct 51 ms 5464 KB Output is correct
51 Correct 17 ms 5724 KB Output is correct
52 Correct 17 ms 5724 KB Output is correct
53 Correct 63 ms 5940 KB Output is correct
54 Correct 20 ms 5980 KB Output is correct
55 Correct 20 ms 6180 KB Output is correct
56 Correct 69 ms 5972 KB Output is correct
57 Correct 23 ms 6232 KB Output is correct
58 Correct 22 ms 6236 KB Output is correct
59 Correct 78 ms 6236 KB Output is correct
60 Correct 30 ms 6492 KB Output is correct
61 Correct 33 ms 6492 KB Output is correct
62 Correct 97 ms 6488 KB Output is correct
63 Correct 80 ms 6488 KB Output is correct
64 Correct 137 ms 6480 KB Output is correct
65 Correct 109 ms 6668 KB Output is correct
66 Correct 92 ms 6492 KB Output is correct
67 Correct 88 ms 6492 KB Output is correct
68 Correct 44 ms 6484 KB Output is correct
69 Correct 43 ms 6472 KB Output is correct
70 Correct 42 ms 6688 KB Output is correct
71 Correct 42 ms 6484 KB Output is correct
72 Correct 31 ms 6480 KB Output is correct
73 Correct 36 ms 6740 KB Output is correct
74 Correct 48 ms 6732 KB Output is correct
75 Correct 57 ms 6748 KB Output is correct
76 Correct 55 ms 6740 KB Output is correct
77 Correct 58 ms 6920 KB Output is correct
78 Correct 64 ms 6748 KB Output is correct
79 Correct 44 ms 6748 KB Output is correct
80 Correct 51 ms 6604 KB Output is correct
81 Correct 57 ms 6852 KB Output is correct
82 Correct 56 ms 6736 KB Output is correct
83 Correct 64 ms 6860 KB Output is correct
84 Correct 61 ms 6484 KB Output is correct
85 Correct 63 ms 6856 KB Output is correct
86 Correct 66 ms 6712 KB Output is correct
87 Correct 61 ms 6748 KB Output is correct
88 Correct 66 ms 6832 KB Output is correct
89 Correct 71 ms 6748 KB Output is correct
90 Correct 73 ms 6736 KB Output is correct
91 Correct 66 ms 6736 KB Output is correct
92 Correct 66 ms 6748 KB Output is correct