Submission #386523

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
386523	2021-04-06T18:06:01 Z	SansPapyrus683	Mecho (IOI09_mecho)	C++17	68 / 100	637 ms	9240 KB

mecho

#include <iostream>
#include <vector>
#include <queue>
#include <climits>

using std::cout;
using std::endl;
using std::vector;
using std::pair;

vector<pair<int, int>> neighbors(const pair<int, int>& at, int row_num, int col_num) {
    vector<pair<int, int>> neighbors;
    if (at.first > 0) {
        neighbors.push_back({at.first - 1, at.second});
    }
    if (at.second > 0) {
        neighbors.push_back({at.first, at.second - 1});
    }
    if (at.first < row_num - 1) {
        neighbors.push_back({at.first + 1, at.second});
    }
    if (at.second < col_num - 1) {
        neighbors.push_back({at.first, at.second + 1});
    }
    return neighbors;
}

class Field {
    private:
        const vector<vector<char>> field;
        const int row_num;
        const int col_num;
        pair<int, int> start;
        vector<vector<int>> bee_dists;
    public:
        Field(const vector<vector<char>>& field)
                : field(field), row_num(field.size()), col_num(field[0].size()),
                  bee_dists(row_num, vector<int>(col_num, INT_MAX)) {
            std::queue<pair<int, int>> frontier;
            for (int r = 0; r < row_num; r++) {
                for (int c = 0; c < col_num; c++) {
                    if (field[r][c] == 'H') {
                        frontier.push({r, c});
                        bee_dists[r][c] = 0;
                    } else if (field[r][c] == 'M') {
                        start = {r, c};
                    }
                }
            }
            while (!frontier.empty()) {
                pair<int, int> c = frontier.front();  // c for curr and to reduce my line length
                frontier.pop();
                int n_cost = bee_dists[c.first][c.second] + 1;
                for (const pair<int, int>& n : neighbors(c, row_num, col_num)) {
                    if (n_cost < bee_dists[n.first][n.second]
                            && field[n.first][n.second] != 'T'
                            && field[n.first][n.second] != 'D') {
                        bee_dists[n.first][n.second] = n_cost;
                        frontier.push(n);
                    }
                }
            }
        }

        bool can_go_home(int honey_time, int speed) {
            std::queue<pair<int, int>> frontier;
            vector<vector<int>> min_moves(row_num, vector<int>(col_num, INT_MAX));
            frontier.push(start);
            min_moves[start.first][start.second] = honey_time * speed;
            while (!frontier.empty()) {
                pair<int, int> curr = frontier.front();
                frontier.pop();
                if (field[curr.first][curr.second] == 'D') {
                    return true;
                }
                int n_cost = min_moves[curr.first][curr.second] + 1;
                for (const pair<int, int>& n : neighbors(curr, row_num, col_num)) {
                    if (field[n.first][n.second] != 'T'
                            && (n_cost / speed) < bee_dists[n.first][n.second]
                            && n_cost < min_moves[n.first][n.second]) {
                        min_moves[n.first][n.second] = n_cost;
                        frontier.push(n);
                    }
                }
            }
            return false;
        }
};

// https://oj.uz/problem/view/IOI09_mecho (sample input ommitted)
int main() {
    int side_len;
    int speed;
    std::cin >> side_len >> speed;
    vector<vector<char>> grid(side_len, vector<char>(side_len));
    for (int r = 0; r < side_len; r++) {
        for (int c = 0; c < side_len; c++) {
            std::cin >> grid[r][c];
        }
    }

    Field field(grid);
    int lo = 0;
    int hi = side_len * side_len;
    int valid = -1;
    while (lo <= hi) {
        int mid = (lo + hi) / 2;
        if (field.can_go_home(mid, speed)) {
            valid = mid;
            lo = mid + 1;
        } else {
            hi = mid - 1;
        }
    }
    if (valid == -1) {
      throw -1;
    }
    cout << valid << endl;
}

Subtask #1

68.0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	364 KB	Output is correct
2	Correct	1 ms	364 KB	Output is correct
3	Correct	1 ms	364 KB	Output is correct
4	Correct	1 ms	364 KB	Output is correct
5	Correct	1 ms	364 KB	Output is correct
6	Correct	1 ms	364 KB	Output is correct
7	Correct	427 ms	6840 KB	Output is correct
8	Runtime error	5 ms	620 KB	Execution killed with signal 6
9	Correct	1 ms	364 KB	Output is correct
10	Correct	1 ms	364 KB	Output is correct
11	Correct	1 ms	364 KB	Output is correct
12	Incorrect	1 ms	364 KB	Output isn't correct
13	Incorrect	1 ms	364 KB	Output isn't correct
14	Runtime error	4 ms	620 KB	Execution killed with signal 6
15	Correct	1 ms	364 KB	Output is correct
16	Correct	1 ms	364 KB	Output is correct
17	Correct	1 ms	364 KB	Output is correct
18	Correct	1 ms	364 KB	Output is correct
19	Correct	1 ms	364 KB	Output is correct
20	Correct	1 ms	364 KB	Output is correct
21	Correct	1 ms	364 KB	Output is correct
22	Correct	1 ms	364 KB	Output is correct
23	Correct	1 ms	364 KB	Output is correct
24	Correct	1 ms	364 KB	Output is correct
25	Correct	1 ms	364 KB	Output is correct
26	Correct	2 ms	364 KB	Output is correct
27	Correct	2 ms	364 KB	Output is correct
28	Correct	2 ms	364 KB	Output is correct
29	Correct	2 ms	364 KB	Output is correct
30	Correct	2 ms	364 KB	Output is correct
31	Correct	2 ms	364 KB	Output is correct
32	Correct	2 ms	492 KB	Output is correct
33	Correct	22 ms	1612 KB	Output is correct
34	Correct	20 ms	1612 KB	Output is correct
35	Correct	101 ms	1616 KB	Output is correct
36	Correct	24 ms	1996 KB	Output is correct
37	Correct	26 ms	1996 KB	Output is correct
38	Correct	129 ms	2132 KB	Output is correct
39	Correct	30 ms	2412 KB	Output is correct
40	Correct	33 ms	2560 KB	Output is correct
41	Correct	184 ms	2412 KB	Output is correct
42	Correct	47 ms	2948 KB	Output is correct
43	Correct	41 ms	2956 KB	Output is correct
44	Correct	216 ms	2952 KB	Output is correct
45	Correct	48 ms	3468 KB	Output is correct
46	Correct	49 ms	3452 KB	Output is correct
47	Correct	252 ms	3500 KB	Output is correct
48	Correct	54 ms	3972 KB	Output is correct
49	Correct	57 ms	3972 KB	Output is correct
50	Correct	303 ms	4112 KB	Output is correct
51	Correct	64 ms	4664 KB	Output is correct
52	Correct	70 ms	4664 KB	Output is correct
53	Correct	368 ms	4644 KB	Output is correct
54	Correct	76 ms	5332 KB	Output is correct
55	Correct	78 ms	5392 KB	Output is correct
56	Correct	450 ms	5468 KB	Output is correct
57	Correct	88 ms	6092 KB	Output is correct
58	Correct	92 ms	6100 KB	Output is correct
59	Correct	633 ms	5992 KB	Output is correct
60	Correct	99 ms	6912 KB	Output is correct
61	Correct	101 ms	6884 KB	Output is correct
62	Correct	591 ms	6828 KB	Output is correct
63	Correct	352 ms	6828 KB	Output is correct
64	Correct	637 ms	6932 KB	Output is correct
65	Correct	489 ms	6828 KB	Output is correct
66	Correct	412 ms	6828 KB	Output is correct
67	Runtime error	403 ms	8916 KB	Execution killed with signal 6
68	Correct	181 ms	6860 KB	Output is correct
69	Correct	180 ms	6940 KB	Output is correct
70	Correct	156 ms	6920 KB	Output is correct
71	Correct	160 ms	6892 KB	Output is correct
72	Incorrect	123 ms	6892 KB	Output isn't correct
73	Incorrect	198 ms	6828 KB	Output isn't correct
74	Correct	283 ms	6872 KB	Output is correct
75	Correct	348 ms	6852 KB	Output is correct
76	Correct	302 ms	6932 KB	Output is correct
77	Correct	320 ms	6960 KB	Output is correct
78	Runtime error	370 ms	9240 KB	Execution killed with signal 6
79	Correct	235 ms	6948 KB	Output is correct
80	Correct	295 ms	7064 KB	Output is correct
81	Correct	328 ms	6840 KB	Output is correct
82	Correct	291 ms	6900 KB	Output is correct
83	Correct	417 ms	6848 KB	Output is correct
84	Correct	356 ms	6860 KB	Output is correct
85	Correct	378 ms	6924 KB	Output is correct
86	Correct	408 ms	6884 KB	Output is correct
87	Correct	368 ms	6936 KB	Output is correct
88	Correct	402 ms	6984 KB	Output is correct
89	Correct	410 ms	6824 KB	Output is correct
90	Correct	415 ms	6944 KB	Output is correct
91	Correct	438 ms	6952 KB	Output is correct
92	Correct	438 ms	6964 KB	Output is correct