Submission #637025

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
637025	2022-08-31T08:24:48 Z	thienbao1602	Mecho (IOI09_mecho)	C++17	100 / 100	249 ms	11360 KB

mecho

#include    <bits/stdc++.h>
#define ll long long
#define pi pair<ll, ll>
#define fi first
#define se second
using namespace std;

const int u[] = {0, 1, 0, -1};
const int v[] = {1, 0, -1, 0};

int n, steps;
char grid[805][805];
pi init, home;
vector<pi> honey;

bool check(ll cur, ll dist, ll m)
{
    if (cur % steps == 0)
    {
        return (cur / steps + m < dist);
    } else
    {
        return (cur / steps  + m + 1 <= dist);
    }
}

bool safe(int u, int v)
{
    return (u >= 0 && u < n && v >= 0 && v < n);
}

void solve()
{
    cin >> n >> steps;
    for(int i=0; i<n; i++)
    {
        for(int j=0; j<n; j++)
        {
            cin >> grid[i][j];
            if (grid[i][j] == 'M')
            {
                init = make_pair(i, j);
            }

            if (grid[i][j] == 'D')
            {
                home = make_pair(i, j);
            }

            if (grid[i][j] == 'H')
            {
                honey.push_back({i, j});
            }
        }
    }

    vector<vector<ll>> dist1(n, vector<ll>(n, -1));
    queue<pi> que;
    for(pi x : honey)
    {
        que.push(x);
        dist1[x.fi][x.se] = 0;
    }

    while(!que.empty())
    {
        pi now = que.front(); que.pop();
        int curU = now.fi, curV = now.se;
        for(int i=0; i<4; i++)
        {
            int ux = u[i] + curU, vx = v[i] + curV;
            if (safe(ux, vx) && (grid[ux][vx] == 'G' || grid[ux][vx] == 'M') && dist1[ux][vx] == -1)
            {
                dist1[ux][vx] = dist1[curU][curV] + 1;
                que.push({ux, vx});
            }
        }
    }

    ll l = 0, r = 1e9;
    ll ans =  -1;
    while(l <= r)
    {
        ll m = (l + r) >> 1;
        que.push(init);
        vector<vector<ll>> dis(n, vector<ll>(n, -1));
        dis[init.fi][init.se] = 0;

        if (m < dist1[init.fi][init.se])
        {
            while(!que.empty())
            {
                pi now = que.front(); que.pop();
                int curU = now.fi, curV = now.se;
                for(int i=0; i<4; i++)
                {
                    int ux = curU + u[i], vx = curV + v[i];
                    if (ux == home.fi && vx == home.se)
                    {
                        dis[ux][vx] = dis[curU][curV] + 1;
                        break;
                    }

                    if (safe(ux, vx) && grid[ux][vx] != 'H' && dis[ux][vx] == -1 && check(dis[curU][curV] + 1, dist1[ux][vx], m))
                    {
                        dis[ux][vx] = dis[curU][curV] + 1;
                        que.push({ux, vx});
                    }
                }
            }
        }

        if (dis[home.fi][home.se] == -1)
        {
            r = m - 1;
        } else
        {
            ans = m;
            l = m + 1;
        }
    }
    cout << ans;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    solve();
    return 0;
}

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	1 ms	212 KB	Output is correct
6	Correct	0 ms	340 KB	Output is correct
7	Correct	135 ms	11288 KB	Output is correct
8	Correct	0 ms	340 KB	Output is correct
9	Correct	0 ms	340 KB	Output is correct
10	Correct	1 ms	340 KB	Output is correct
11	Correct	0 ms	340 KB	Output is correct
12	Correct	1 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	340 KB	Output is correct
16	Correct	0 ms	340 KB	Output is correct
17	Correct	0 ms	340 KB	Output is correct
18	Correct	0 ms	340 KB	Output is correct
19	Correct	0 ms	340 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	1 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	0 ms	340 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	468 KB	Output is correct
32	Correct	1 ms	468 KB	Output is correct
33	Correct	13 ms	2548 KB	Output is correct
34	Correct	13 ms	2548 KB	Output is correct
35	Correct	28 ms	2556 KB	Output is correct
36	Correct	15 ms	3176 KB	Output is correct
37	Correct	15 ms	3248 KB	Output is correct
38	Correct	37 ms	3268 KB	Output is correct
39	Correct	19 ms	3968 KB	Output is correct
40	Correct	23 ms	3960 KB	Output is correct
41	Correct	50 ms	3884 KB	Output is correct
42	Correct	22 ms	4756 KB	Output is correct
43	Correct	23 ms	4672 KB	Output is correct
44	Correct	65 ms	4740 KB	Output is correct
45	Correct	30 ms	5732 KB	Output is correct
46	Correct	28 ms	5628 KB	Output is correct
47	Correct	82 ms	5616 KB	Output is correct
48	Correct	36 ms	6564 KB	Output is correct
49	Correct	40 ms	6592 KB	Output is correct
50	Correct	105 ms	6584 KB	Output is correct
51	Correct	43 ms	7556 KB	Output is correct
52	Correct	43 ms	7668 KB	Output is correct
53	Correct	124 ms	7636 KB	Output is correct
54	Correct	52 ms	8656 KB	Output is correct
55	Correct	52 ms	8748 KB	Output is correct
56	Correct	148 ms	8736 KB	Output is correct
57	Correct	57 ms	9904 KB	Output is correct
58	Correct	54 ms	9884 KB	Output is correct
59	Correct	172 ms	9908 KB	Output is correct
60	Correct	69 ms	11228 KB	Output is correct
61	Correct	65 ms	11236 KB	Output is correct
62	Correct	202 ms	11152 KB	Output is correct
63	Correct	165 ms	11236 KB	Output is correct
64	Correct	249 ms	11180 KB	Output is correct
65	Correct	244 ms	11136 KB	Output is correct
66	Correct	189 ms	11200 KB	Output is correct
67	Correct	167 ms	11144 KB	Output is correct
68	Correct	107 ms	11228 KB	Output is correct
69	Correct	100 ms	11220 KB	Output is correct
70	Correct	78 ms	11184 KB	Output is correct
71	Correct	83 ms	11176 KB	Output is correct
72	Correct	83 ms	11200 KB	Output is correct
73	Correct	90 ms	11360 KB	Output is correct
74	Correct	105 ms	11256 KB	Output is correct
75	Correct	113 ms	11232 KB	Output is correct
76	Correct	107 ms	11232 KB	Output is correct
77	Correct	119 ms	11236 KB	Output is correct
78	Correct	118 ms	11264 KB	Output is correct
79	Correct	102 ms	11248 KB	Output is correct
80	Correct	106 ms	11284 KB	Output is correct
81	Correct	112 ms	11312 KB	Output is correct
82	Correct	113 ms	11336 KB	Output is correct
83	Correct	130 ms	11244 KB	Output is correct
84	Correct	124 ms	11224 KB	Output is correct
85	Correct	114 ms	11236 KB	Output is correct
86	Correct	129 ms	11244 KB	Output is correct
87	Correct	126 ms	11196 KB	Output is correct
88	Correct	160 ms	11260 KB	Output is correct
89	Correct	130 ms	11244 KB	Output is correct
90	Correct	133 ms	11232 KB	Output is correct
91	Correct	131 ms	11256 KB	Output is correct
92	Correct	142 ms	11276 KB	Output is correct