Submission #689591

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
689591	2023-01-28T19:25:22 Z	pls33	Mecho (IOI09_mecho)	C++17	100 / 100	350 ms	13940 KB

mecho

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

#pragma region dalykai
using p32 = pair<int, int>;
using p32u = pair<uint32_t, uint32_t>;
using p64 = pair<int64_t, int64_t>;
using p64u = pair<uint64_t, uint64_t>;
using vi16 = vector<int16_t>;
using vi16u = vector<uint16_t>;
using vi32 = vector<int>;
using vi32u = vector<uint32_t>;
using vi64 = vector<int64_t>;
using vi64u = vector<uint64_t>;
using vp32 = vector<p32>;
using vp32u = vector<p32u>;
using vp64 = vector<p64>;
using vp64u = vector<p64u>;
using vvi32 = vector<vi32>;
using vvi32u = vector<vi32u>;
using vvi64 = vector<vi64>;
using vvi64u = vector<vi64u>;
using vvp32 = vector<vp32>;
using vvp32u = vector<vp32u>;
using vvp64 = vector<vp64>;
using vvp64u = vector<vp64u>;
#pragma endregion

using grid_t = vector<string>;

const vi32 dx = {1, -1, 0, 0};
const vi32 dy = {0, 0, 1, -1};

struct frac_t
{
    int64_t enumer, denomin;

    frac_t(int64_t e = 0, int64_t d = 1)
    {
        enumer = e;
        denomin = d;
    }

    frac_t operator+(frac_t rhs)
    {
        int64_t d = lcm(denomin, rhs.denomin);
        int64_t e = enumer * (d / denomin) + rhs.enumer * (d / rhs.denomin);

        return {e, d};
    }

    bool operator<(frac_t rhs)
    {
        int64_t d = lcm(denomin, rhs.denomin);
        return enumer * (d / denomin) < rhs.enumer * (d / rhs.denomin);
    }

    bool operator>=(frac_t rhs)
    {
        int64_t d = lcm(denomin, rhs.denomin);
        return enumer * (d / denomin) >= rhs.enumer * (d / rhs.denomin);
    }

    bool operator<(int64_t rhs)
    {
        return *this < frac_t(rhs, 1);
    }

    bool operator>=(int64_t rhs)
    {
        return *this >= frac_t(rhs, 1);
    }

    double approx()
    {
        return (double)enumer / (double)denomin;
    }
};

using bear_t = vector<vector<frac_t>>;

bool inside(p32 pos, int n)
{
    return pos.first >= 0 && pos.first < n &&
           pos.second >= 0 && pos.second < n;
}

void get_time(vp32 &hive, vvi32 &reach_time, grid_t &grid)
{
    queue<p32> q;
    for (auto &h : hive)
    {
        q.push(h);
        reach_time[h.first][h.second] = 0;
    }

    while (!q.empty())
    {
        p32 cur = q.front();
        q.pop();

        for (int i = 0; i < (int)dx.size(); i++)
        {
            p32 next = {cur.first + dx[i], cur.second + dy[i]};

            if (inside(next, (int)grid.size()) && grid[next.first][next.second] == 'M' &&
                reach_time[next.first][next.second] == INT_MAX)
            {
                reach_time[next.first][next.second] = reach_time[cur.first][cur.second] + 1;
            }

            if (!inside(next, (int)grid.size()) ||
                grid[next.first][next.second] != 'G' ||
                reach_time[next.first][next.second] != INT_MAX)
            {
                continue;
            }

            reach_time[next.first][next.second] = reach_time[cur.first][cur.second] + 1;
            q.push(next);
        }
    }
}

bool can_reach(p32 start, p32 end, int time, frac_t speed,
               vvi32 &reach_time, bear_t &bear_time, grid_t &grid)
{
    if (time >= reach_time[start.first][start.second])
    {
        return false;
    }
    bear_time[start.first][start.second] = frac_t(time, 1);
    queue<p32> q;
    q.push(start);

    while (!q.empty())
    {
        p32 cur = q.front();
        q.pop();

        for (int i = 0; i < (int)dx.size(); i++)
        {
            p32 next = {cur.first + dx[i], cur.second + dy[i]};
            frac_t cur_time = bear_time[cur.first][cur.second] + speed;

            if (!inside(next, (int)grid.size()) ||
                (grid[next.first][next.second] != 'G' &&
                 grid[next.first][next.second] != 'D') ||
                bear_time[next.first][next.second].enumer != -1 ||
                cur_time >= reach_time[next.first][next.second])
            {
                continue;
            }

            bear_time[next.first][next.second] = cur_time;

            if (next == end)
            {
                return true;
            }

            q.push(next);
        }
    }

    return false;
}

bool test_reach(p32 start, p32 end, int time, int s,
                vvi32 &reach_time, bear_t &bear_time, grid_t &grid)
{
    frac_t speed(1, s);
    bool result = can_reach(start, end, time, speed, reach_time, bear_time, grid);

    for (auto &row : bear_time)
    {
        for (auto &b : row)
        {
            b = frac_t(-1, 1);
        }
    }

    return result;
}

int main()
{
#ifndef _AAAAAAAAA
    ios_base::sync_with_stdio(false);
    cin.tie(0);
#else
    freopen("mecho.in", "r", stdin);
#ifndef __linux__
    atexit([]()
           {
        freopen("con", "r", stdin);
        system("pause"); });
#endif
#endif

    int n, s;
    cin >> n >> s;

    grid_t grid(n);
    vp32 hive;
    p32 start, end;
    {
        int i = 0;
        for (auto &row : grid)
        {
            cin >> row;
            for (int j = 0; j < (int)row.size(); j++)
            {
                switch (row[j])
                {
                case 'M':
                {
                    start = {i, j};
                    break;
                }
                case 'D':
                {
                    end = {i, j};
                    break;
                }
                case 'H':
                {
                    hive.emplace_back(i, j);
                    break;
                }
                }
            }

            i++;
        }
    }

    vvi32 reach_time(n, vi32(n, INT_MAX));
    bear_t bear_time(n, vector<frac_t>(n, frac_t(-1, -1)));
    get_time(hive, reach_time, grid);

    int result = 0;
    for (int bit = 29; bit >= 0; bit--)
    {
        int cur = result + (1 << bit);
        if (cur > n * n || !test_reach(start, end, cur, s, reach_time, bear_time, grid))
        {
            continue;
        }

        result = cur;
    }

    if (!result)
    {
        bool cant = !test_reach(start, end, 0, s, reach_time, bear_time, grid);
        result = cant ? -1 : result;
    }
    cout << result << '\n';

    return 0;
}

Compilation message

mecho.cpp:8: warning: ignoring '#pragma region dalykai' [-Wunknown-pragmas]
    8 | #pragma region dalykai
      | 
mecho.cpp:31: warning: ignoring '#pragma endregion ' [-Wunknown-pragmas]
   31 | #pragma endregion
      |

Subtask #1

100.0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	212 KB	Output is correct
2	Correct	0 ms	212 KB	Output is correct
3	Correct	0 ms	212 KB	Output is correct
4	Correct	0 ms	212 KB	Output is correct
5	Correct	0 ms	212 KB	Output is correct
6	Correct	0 ms	212 KB	Output is correct
7	Correct	234 ms	13720 KB	Output is correct
8	Correct	0 ms	212 KB	Output is correct
9	Correct	0 ms	212 KB	Output is correct
10	Correct	0 ms	212 KB	Output is correct
11	Correct	0 ms	212 KB	Output is correct
12	Correct	0 ms	340 KB	Output is correct
13	Correct	1 ms	340 KB	Output is correct
14	Correct	1 ms	340 KB	Output is correct
15	Correct	0 ms	212 KB	Output is correct
16	Correct	1 ms	212 KB	Output is correct
17	Correct	1 ms	212 KB	Output is correct
18	Correct	0 ms	212 KB	Output is correct
19	Correct	1 ms	212 KB	Output is correct
20	Correct	0 ms	340 KB	Output is correct
21	Correct	1 ms	340 KB	Output is correct
22	Correct	1 ms	340 KB	Output is correct
23	Correct	1 ms	340 KB	Output is correct
24	Correct	1 ms	340 KB	Output is correct
25	Correct	0 ms	340 KB	Output is correct
26	Correct	1 ms	340 KB	Output is correct
27	Correct	1 ms	340 KB	Output is correct
28	Correct	1 ms	412 KB	Output is correct
29	Correct	1 ms	340 KB	Output is correct
30	Correct	1 ms	340 KB	Output is correct
31	Correct	1 ms	340 KB	Output is correct
32	Correct	1 ms	340 KB	Output is correct
33	Correct	4 ms	2772 KB	Output is correct
34	Correct	5 ms	2776 KB	Output is correct
35	Correct	57 ms	2868 KB	Output is correct
36	Correct	6 ms	3676 KB	Output is correct
37	Correct	9 ms	3540 KB	Output is correct
38	Correct	84 ms	3644 KB	Output is correct
39	Correct	8 ms	4436 KB	Output is correct
40	Correct	9 ms	4436 KB	Output is correct
41	Correct	98 ms	4436 KB	Output is correct
42	Correct	12 ms	5460 KB	Output is correct
43	Correct	11 ms	5460 KB	Output is correct
44	Correct	119 ms	5520 KB	Output is correct
45	Correct	12 ms	6612 KB	Output is correct
46	Correct	12 ms	6612 KB	Output is correct
47	Correct	158 ms	6612 KB	Output is correct
48	Correct	14 ms	7764 KB	Output is correct
49	Correct	15 ms	7764 KB	Output is correct
50	Correct	199 ms	7808 KB	Output is correct
51	Correct	19 ms	9044 KB	Output is correct
52	Correct	17 ms	9044 KB	Output is correct
53	Correct	230 ms	9092 KB	Output is correct
54	Correct	21 ms	10516 KB	Output is correct
55	Correct	26 ms	10452 KB	Output is correct
56	Correct	275 ms	10492 KB	Output is correct
57	Correct	28 ms	11988 KB	Output is correct
58	Correct	29 ms	11988 KB	Output is correct
59	Correct	323 ms	11988 KB	Output is correct
60	Correct	36 ms	13524 KB	Output is correct
61	Correct	37 ms	13524 KB	Output is correct
62	Correct	350 ms	13580 KB	Output is correct
63	Correct	207 ms	13524 KB	Output is correct
64	Correct	289 ms	13600 KB	Output is correct
65	Correct	305 ms	13524 KB	Output is correct
66	Correct	239 ms	13600 KB	Output is correct
67	Correct	245 ms	13600 KB	Output is correct
68	Correct	102 ms	13620 KB	Output is correct
69	Correct	76 ms	13524 KB	Output is correct
70	Correct	67 ms	13536 KB	Output is correct
71	Correct	71 ms	13616 KB	Output is correct
72	Correct	52 ms	13524 KB	Output is correct
73	Correct	64 ms	13780 KB	Output is correct
74	Correct	157 ms	13872 KB	Output is correct
75	Correct	172 ms	13888 KB	Output is correct
76	Correct	158 ms	13908 KB	Output is correct
77	Correct	169 ms	13888 KB	Output is correct
78	Correct	224 ms	13856 KB	Output is correct
79	Correct	130 ms	13852 KB	Output is correct
80	Correct	149 ms	13844 KB	Output is correct
81	Correct	182 ms	13856 KB	Output is correct
82	Correct	158 ms	13852 KB	Output is correct
83	Correct	227 ms	13768 KB	Output is correct
84	Correct	188 ms	13940 KB	Output is correct
85	Correct	187 ms	13780 KB	Output is correct
86	Correct	201 ms	13816 KB	Output is correct
87	Correct	193 ms	13808 KB	Output is correct
88	Correct	237 ms	13652 KB	Output is correct
89	Correct	214 ms	13756 KB	Output is correct
90	Correct	257 ms	13752 KB	Output is correct
91	Correct	216 ms	13756 KB	Output is correct
92	Correct	213 ms	13752 KB	Output is correct