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Submission #1012641

# Submission time Handle Problem Language Result Execution time Memory
1012641 2024-07-02T12:47:56 Z toast12 Mecho (IOI09_mecho) C++14
100 / 100
 157 ms 6464 KB 
#include <bits/stdc++.h>
using namespace std;
 
const int MAXN = 800;
 
int n, s;
vector<vector<char>> grid;
vector<vector<int>> dist;
 
int honey;
 
bool reachable(int mecho, int bee) {
    return (((mecho-honey)/s < bee-honey) && mecho != -1); 
}
 
void bfs(queue<pair<int, int>> &q, vector<vector<int>> &d) {
    while (!q.empty()) {
        int x = q.front().first;
        int y = q.front().second;
        q.pop();
        if (x < 1 || y < 1 || x > n || y > n)
            continue;
        if (d[x+1][y] == -1 && grid[x+1][y] == '.' && reachable(d[x][y]+1, dist[x+1][y])) {
            q.push({x+1, y});
            d[x+1][y] = d[x][y]+1;
        }
        if (d[x-1][y] == -1 && grid[x-1][y] == '.' && reachable(d[x][y]+1, dist[x-1][y])) {
            q.push({x-1, y});
            d[x-1][y] = d[x][y]+1;
        }
        if (d[x][y+1] == -1 && grid[x][y+1] == '.' && reachable(d[x][y]+1, dist[x][y+1])) {
            q.push({x, y+1});
            d[x][y+1] = d[x][y]+1;
        }
        if (d[x][y-1] == -1 && grid[x][y-1] == '.' && reachable(d[x][y]+1, dist[x][y-1])) {
            q.push({x, y-1});
            d[x][y-1] = d[x][y]+1;
        }
    }
}
 
int main() {
    // ios_base::sync_with_stdio(0);
    // cin.tie(NULL);
    cin >> n >> s;
    grid.resize(n+2, vector<char>(n+2, '.'));
    pair<int, int> start, end;
    queue<pair<int, int>> q;
    dist.resize(n+2, vector<int>(n+2, -1));
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            cin >> grid[i][j];
            if (grid[i][j] == 'G')
                grid[i][j] = '.';
            else if (grid[i][j] == 'T')
                grid[i][j] = 'X';
            else if (grid[i][j] == 'M') {
                start = {i, j};
                grid[i][j] = '.';
            }
            else if (grid[i][j] == 'D') {
                end = {i, j};
                grid[i][j] = 'X';
            }
            else {
                q.push({i, j});
                dist[i][j] = 0;
            }
        }
    }
    // distance for bees
    while (!q.empty()) {
        int x = q.front().first;
        int y = q.front().second;
        q.pop();
        if (x < 1 || y < 1 || x > n || y > n)
            continue;
        if (dist[x+1][y] == -1 && grid[x+1][y] == '.') {
            q.push({x+1, y});
            dist[x+1][y] = dist[x][y]+1;
        }
        if (dist[x-1][y] == -1 && grid[x-1][y] == '.') {
            q.push({x-1, y});
            dist[x-1][y] = dist[x][y]+1;
        }
        if (dist[x][y+1] == -1 && grid[x][y+1] == '.') {
            q.push({x, y+1});
            dist[x][y+1] = dist[x][y]+1;
        }
        if (dist[x][y-1] == -1 && grid[x][y-1] == '.') {
            q.push({x, y-1});
            dist[x][y-1] = dist[x][y]+1;
        }
    }
    int lo = 0, hi = n*n;
    int ans = -1;
    while (lo <= hi) {
        int mid = (lo+hi)/2;
        // cout << mid << '\n';
        vector<vector<int>> d(n+2, vector<int>(n+2, -1));
        d[start.first][start.second] = mid;
        honey = mid;
        q.push(start);
        if (dist[start.first][start.second] <= mid)
            q.pop();
        bfs(q, d);
        bool poss = reachable(d[end.first-1][end.second], dist[end.first-1][end.second]);
        poss |= reachable(d[end.first+1][end.second], dist[end.first+1][end.second]);
        poss |= reachable(d[end.first][end.second-1], dist[end.first][end.second-1]);
        poss |= reachable(d[end.first][end.second+1], dist[end.first][end.second+1]);
        if (poss) {
            lo = mid+1;
            ans = mid;
        }
        else {
            hi = mid-1;
        }
    }
    cout << ans << '\n';
    return 0;
}

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 344 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 70 ms 6232 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 1 ms 348 KB Output is correct
12 Correct 1 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 1 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 1 ms 348 KB Output is correct
19 Correct 1 ms 348 KB Output is correct
20 Correct 1 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct
22 Correct 1 ms 348 KB Output is correct
23 Correct 0 ms 348 KB Output is correct
24 Correct 0 ms 348 KB Output is correct
25 Correct 0 ms 348 KB Output is correct
26 Correct 1 ms 348 KB Output is correct
27 Correct 1 ms 348 KB Output is correct
28 Correct 1 ms 344 KB Output is correct
29 Correct 1 ms 348 KB Output is correct
30 Correct 1 ms 348 KB Output is correct
31 Correct 1 ms 348 KB Output is correct
32 Correct 0 ms 348 KB Output is correct
33 Correct 7 ms 1548 KB Output is correct
34 Correct 8 ms 1596 KB Output is correct
35 Correct 16 ms 1568 KB Output is correct
36 Correct 10 ms 1880 KB Output is correct
37 Correct 12 ms 1884 KB Output is correct
38 Correct 22 ms 1764 KB Output is correct
39 Correct 12 ms 2332 KB Output is correct
40 Correct 14 ms 2284 KB Output is correct
41 Correct 40 ms 2292 KB Output is correct
42 Correct 16 ms 2744 KB Output is correct
43 Correct 15 ms 2764 KB Output is correct
44 Correct 33 ms 2740 KB Output is correct
45 Correct 19 ms 3224 KB Output is correct
46 Correct 18 ms 3164 KB Output is correct
47 Correct 39 ms 3212 KB Output is correct
48 Correct 22 ms 3736 KB Output is correct
49 Correct 25 ms 3684 KB Output is correct
50 Correct 51 ms 3716 KB Output is correct
51 Correct 26 ms 4216 KB Output is correct
52 Correct 26 ms 4284 KB Output is correct
53 Correct 66 ms 4252 KB Output is correct
54 Correct 31 ms 4884 KB Output is correct
55 Correct 37 ms 4884 KB Output is correct
56 Correct 80 ms 4856 KB Output is correct
57 Correct 35 ms 5520 KB Output is correct
58 Correct 35 ms 5536 KB Output is correct
59 Correct 75 ms 5540 KB Output is correct
60 Correct 40 ms 6220 KB Output is correct
61 Correct 45 ms 6184 KB Output is correct
62 Correct 85 ms 6180 KB Output is correct
63 Correct 89 ms 6172 KB Output is correct
64 Correct 157 ms 6156 KB Output is correct
65 Correct 123 ms 6208 KB Output is correct
66 Correct 97 ms 6172 KB Output is correct
67 Correct 97 ms 6172 KB Output is correct
68 Correct 70 ms 6204 KB Output is correct
69 Correct 59 ms 6224 KB Output is correct
70 Correct 52 ms 6216 KB Output is correct
71 Correct 56 ms 6256 KB Output is correct
72 Correct 45 ms 6464 KB Output is correct
73 Correct 42 ms 6216 KB Output is correct
74 Correct 53 ms 6196 KB Output is correct
75 Correct 62 ms 6248 KB Output is correct
76 Correct 53 ms 6224 KB Output is correct
77 Correct 53 ms 6228 KB Output is correct
78 Correct 65 ms 6240 KB Output is correct
79 Correct 51 ms 6208 KB Output is correct
80 Correct 54 ms 6240 KB Output is correct
81 Correct 57 ms 6232 KB Output is correct
82 Correct 61 ms 6236 KB Output is correct
83 Correct 64 ms 6236 KB Output is correct
84 Correct 60 ms 6228 KB Output is correct
85 Correct 60 ms 6228 KB Output is correct
86 Correct 63 ms 6204 KB Output is correct
87 Correct 69 ms 6272 KB Output is correct
88 Correct 58 ms 6308 KB Output is correct
89 Correct 63 ms 6236 KB Output is correct
90 Correct 86 ms 6200 KB Output is correct
91 Correct 64 ms 6276 KB Output is correct
92 Correct 71 ms 6244 KB Output is correct