답안 #401055

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
401055	2021-05-09T09:32:16 Z	ruadhan	Mecho (IOI09_mecho)	C++17	100 / 100	299 ms	6436 KB

mecho

#include <bits/stdc++.h>
#define sz(x) (int)x.size()
#define x first
#define y second
#define X 0
#define Y 1
#define TIME 2
#define STEPS 3
using namespace std;
typedef pair<int, int> pi;

const int MX = 805;
string grid[MX];
int bees_time[MX][MX];
int N, S;

vector<pi> hives;
vector<pi> dirs = {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
void calc_bee_times()
{
    queue<pi> q;
    for (auto i : hives)
    {
        q.push(i);
        bees_time[i.x][i.y] = 0;
    }
    while (!q.empty())
    {
        auto curr = q.front();
        q.pop();
        for (auto d : dirs)
        {
            int i = curr.x + d.x, j = curr.y + d.y;
            if (i < 0 || i >= N || j < 0 || j >= N || grid[i][j] == 'T' || grid[i][j] == 'D' || bees_time[i][j] != -1)
                continue;
            bees_time[i][j] = bees_time[curr.x][curr.y] + 1;
            q.push({i, j});
        }
    }
}

pi mecho, home;
int processed[MX][MX];
bool ok(int t)
{
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < N; j++)
            processed[i][j] = -1;
    }

    if (bees_time[mecho.x][mecho.y] <= t)
        return false;

    queue<pi> q;
    processed[mecho.x][mecho.y] = 0;

    q.push(mecho);
    while (!q.empty())
    {
        auto curr = q.front();

        // cout << "new queue top = " << curr.x << " " << curr.y << ", d=" << processed[curr.x][curr.y] << '\n';

        q.pop();
        for (auto d : dirs)
        {
            int i = curr.x + d.x, j = curr.y + d.y;

            if (i < 0 || i >= N || j < 0 || j >= N || grid[i][j] == 'T' || (bees_time[i][j] <= t + (processed[curr.x][curr.y] + 1) / S && make_pair(i, j) != home) || processed[i][j] != -1)
                continue;

            // cout << "we can go to " << i << ", " << j << " from here with steps = " << processed[curr.x][curr.y] + 1 << ", moves = " << (processed[curr.x][curr.y] + 1) / S << '\n';

            processed[i][j] = processed[curr.x][curr.y] + 1;
            q.push({i, j});
        }
    }
    return processed[home.x][home.y] != -1;
}

int main()
{
    cin >> N >> S;
    for (int i = 0; i < MX; i++)
        for (int j = 0; j < MX; j++)
            bees_time[i][j] = -1;

    for (int i = 0; i < N; i++)
    {
        cin >> grid[i];
        for (int j = 0; j < N; j++)
        {
            if (grid[i][j] == 'H')
                hives.push_back({i, j});
            else if (grid[i][j] == 'M')
                mecho.x = i, mecho.y = j;
            else if (grid[i][j] == 'D')
                home.x = i, home.y = j;
        }
    }

    calc_bee_times();

    // cout << ok(2) << '\n';

    // for (int i = 0; i < N; i++)
    // {
    //     for (int j = 0; j < N; j++)
    //         cout << bees_time[i][j] << " ";
    //     cout << '\n';
    // }

    int lo = 0, hi = 800 * 800;
    for (int b = hi / 2; b >= 1; b /= 2)
    {
        while (lo + b < hi && ok(lo + b))
            lo += b;
    }

    if (lo == 0 && !ok(0))
        cout << -1 << '\n';
    else
        cout << lo << '\n';

    return 0;
}

Subtask #1

100.0 / 100.0

#	결과	실행 시간	메모리	Grader output
1	Correct	2 ms	2764 KB	Output is correct
2	Correct	2 ms	2764 KB	Output is correct
3	Correct	2 ms	2764 KB	Output is correct
4	Correct	2 ms	2764 KB	Output is correct
5	Correct	2 ms	2764 KB	Output is correct
6	Correct	2 ms	2764 KB	Output is correct
7	Correct	153 ms	6272 KB	Output is correct
8	Correct	2 ms	2892 KB	Output is correct
9	Correct	2 ms	2892 KB	Output is correct
10	Correct	2 ms	2892 KB	Output is correct
11	Correct	2 ms	2892 KB	Output is correct
12	Correct	2 ms	2944 KB	Output is correct
13	Correct	2 ms	3020 KB	Output is correct
14	Correct	3 ms	3020 KB	Output is correct
15	Correct	2 ms	2892 KB	Output is correct
16	Correct	2 ms	2892 KB	Output is correct
17	Correct	2 ms	2892 KB	Output is correct
18	Correct	2 ms	2892 KB	Output is correct
19	Correct	2 ms	2892 KB	Output is correct
20	Correct	2 ms	2892 KB	Output is correct
21	Correct	2 ms	2892 KB	Output is correct
22	Correct	2 ms	2892 KB	Output is correct
23	Correct	2 ms	3020 KB	Output is correct
24	Correct	2 ms	3020 KB	Output is correct
25	Correct	3 ms	3020 KB	Output is correct
26	Correct	2 ms	3020 KB	Output is correct
27	Correct	3 ms	3020 KB	Output is correct
28	Correct	3 ms	3020 KB	Output is correct
29	Correct	3 ms	3020 KB	Output is correct
30	Correct	3 ms	3020 KB	Output is correct
31	Correct	3 ms	3020 KB	Output is correct
32	Correct	3 ms	3020 KB	Output is correct
33	Correct	10 ms	4044 KB	Output is correct
34	Correct	9 ms	4044 KB	Output is correct
35	Correct	36 ms	4172 KB	Output is correct
36	Correct	13 ms	4320 KB	Output is correct
37	Correct	13 ms	4300 KB	Output is correct
38	Correct	44 ms	4300 KB	Output is correct
39	Correct	14 ms	4472 KB	Output is correct
40	Correct	15 ms	4492 KB	Output is correct
41	Correct	55 ms	4412 KB	Output is correct
42	Correct	17 ms	4812 KB	Output is correct
43	Correct	18 ms	4912 KB	Output is correct
44	Correct	69 ms	4908 KB	Output is correct
45	Correct	25 ms	5068 KB	Output is correct
46	Correct	22 ms	5060 KB	Output is correct
47	Correct	89 ms	5068 KB	Output is correct
48	Correct	26 ms	5232 KB	Output is correct
49	Correct	22 ms	5224 KB	Output is correct
50	Correct	98 ms	5324 KB	Output is correct
51	Correct	26 ms	5452 KB	Output is correct
52	Correct	27 ms	5532 KB	Output is correct
53	Correct	128 ms	5516 KB	Output is correct
54	Correct	30 ms	5700 KB	Output is correct
55	Correct	30 ms	5732 KB	Output is correct
56	Correct	141 ms	5708 KB	Output is correct
57	Correct	33 ms	5996 KB	Output is correct
58	Correct	37 ms	5812 KB	Output is correct
59	Correct	166 ms	5944 KB	Output is correct
60	Correct	43 ms	6084 KB	Output is correct
61	Correct	45 ms	6044 KB	Output is correct
62	Correct	185 ms	6016 KB	Output is correct
63	Correct	134 ms	6132 KB	Output is correct
64	Correct	299 ms	6136 KB	Output is correct
65	Correct	201 ms	6128 KB	Output is correct
66	Correct	186 ms	6132 KB	Output is correct
67	Correct	150 ms	6256 KB	Output is correct
68	Correct	89 ms	6084 KB	Output is correct
69	Correct	86 ms	6096 KB	Output is correct
70	Correct	54 ms	6084 KB	Output is correct
71	Correct	57 ms	6072 KB	Output is correct
72	Correct	62 ms	6064 KB	Output is correct
73	Correct	66 ms	6340 KB	Output is correct
74	Correct	95 ms	6436 KB	Output is correct
75	Correct	121 ms	6340 KB	Output is correct
76	Correct	108 ms	6340 KB	Output is correct
77	Correct	121 ms	6404 KB	Output is correct
78	Correct	118 ms	6436 KB	Output is correct
79	Correct	82 ms	6340 KB	Output is correct
80	Correct	108 ms	6404 KB	Output is correct
81	Correct	122 ms	6304 KB	Output is correct
82	Correct	102 ms	6404 KB	Output is correct
83	Correct	131 ms	6360 KB	Output is correct
84	Correct	140 ms	6276 KB	Output is correct
85	Correct	161 ms	6252 KB	Output is correct
86	Correct	127 ms	6264 KB	Output is correct
87	Correct	153 ms	6356 KB	Output is correct
88	Correct	129 ms	6284 KB	Output is correct
89	Correct	143 ms	6244 KB	Output is correct
90	Correct	140 ms	6212 KB	Output is correct
91	Correct	169 ms	6340 KB	Output is correct
92	Correct	141 ms	6300 KB	Output is correct