Submission #839394

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
839394	2023-08-29T23:45:16 Z	ArashJafariyan	Mecho (IOI09_mecho)	C++17	100 / 100	210 ms	6540 KB

mecho

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;

#define F first
#define S second
#define pb push_back
#define size(a) (int) a.size()
#define all(a) a.begin(), a.end()

const int maxn = 800 + 4, inf = 1e8;

int n, s, mx, my, dx, dy, d[maxn][maxn], save[maxn][maxn];
bitset<maxn> vis[maxn], savevis[maxn];
string a[maxn];
queue<array<int, 2>> q;

void rest() {
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            vis[i][j] = 0;
            d[i][j] = inf;
        }
    }
    return;
}

bool check0(int x, int y) {
    bool ret = ((0 <= x) && (x < n));
    ret &= ((0 <= y) && (y < n));
    if (ret) {
        ret &= (!vis[x][y]);
        ret &= ((a[x][y] == 'G') || (a[x][y] == 'M'));
    }
    return ret;
}

void upd0(int x, int y) { 
    int dis = d[x][y] + 1;

    if (check0(x - 1, y)) {
        vis[x - 1][y] = 1;
        d[x - 1][y] = dis;
        q.push({x - 1, y});
    }
    if (check0(x + 1, y)) {
        vis[x + 1][y] = 1;
        d[x + 1][y] = dis;
        q.push({x + 1, y});
    }
    if (check0(x, y - 1)) {
        vis[x][y - 1] = 1;
        d[x][y - 1] = dis;
        q.push({x, y - 1});
    }
    if (check0(x, y + 1)) {
        vis[x][y + 1] = 1;
        d[x][y + 1] = dis;
        q.push({x, y + 1});
    }
}

bool check1(int x, int y, int dis, int k) {
    bool ret = ((0 <= x) && (x < n));
    ret &= ((0 <= y) && (y < n));
    if (ret) {
        ret &= (!vis[x][y]);
        ret &= ((a[x][y] == 'G') || (a[x][y] == 'D'));
        ret &= ((((dis + s - 1) / s) <= (save[x][y] - k)) || !savevis[x][y]);
    }
    return ret;
}

void upd1(int x, int y, int k) {
    int dis = d[x][y] + 1;
    
    if (check1(x - 1, y, dis, k)) {
        vis[x - 1][y] = 1;
        d[x - 1][y] = dis;
        q.push({x - 1, y});
    }
    if (check1(x + 1, y, dis, k)) {
        vis[x + 1][y] = 1;
        d[x + 1][y] = dis;
        q.push({x + 1, y});
    }
    if (check1(x, y - 1, dis, k)) {
        vis[x][y - 1] = 1;
        d[x][y - 1] = dis;
        q.push({x, y - 1});
    }
    if (check1(x, y + 1, dis, k)) {
        vis[x][y + 1] = 1;
        d[x][y + 1] = dis;
        q.push({x, y + 1});
    }
}

bool bfs(int k) {
    rest();

    d[mx][my] = 0;
    vis[mx][my] = 1;
    q.push({mx, my});
    while (!q.empty()) {
        array<int, 2> v = q.front();
        q.pop();
        if (d[v[0]][v[1]] % s == 0 && d[v[0]][v[1]] / s == save[v[0]][v[1]] - k) {
            continue;
        }
        upd1(v[0], v[1], k);
    }
    
    return (d[dx][dy] != inf);
}

int main() {
    ios::sync_with_stdio(0), cin.tie(0);

    cin >> n >> s;
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
    }

    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            if (a[i][j] == 'H') {
                q.push({i, j});
                vis[i][j] = 1;
            }
        }
    }

    while (!q.empty()) {
        array<int, 2> v = q.front();
        q.pop();
        upd0(v[0], v[1]);
    }

    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            if (a[i][j] == 'M') {
                mx = i;
                my = j;
            }
            if (a[i][j] == 'D') {
                dx = i;
                dy = j;
            }
            save[i][j] = d[i][j];
            savevis[i][j] = vis[i][j];
        }
    }

    int l, r;
    l = -1;
    r = save[mx][my];

    while (r - l > 1) {
        int m = (l + r) >> 1;
        if (bfs(m)) {
            l = m;
        }
        else {
            r = m;
        }
    }
    cout << l << '\n';

    return 0;
}

Subtask #1

100.0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	340 KB	Output is correct
2	Correct	0 ms	340 KB	Output is correct
3	Correct	0 ms	340 KB	Output is correct
4	Correct	1 ms	340 KB	Output is correct
5	Correct	0 ms	340 KB	Output is correct
6	Correct	1 ms	340 KB	Output is correct
7	Correct	99 ms	6228 KB	Output is correct
8	Correct	0 ms	464 KB	Output is correct
9	Correct	1 ms	340 KB	Output is correct
10	Correct	0 ms	340 KB	Output is correct
11	Correct	1 ms	340 KB	Output is correct
12	Correct	1 ms	724 KB	Output is correct
13	Correct	1 ms	596 KB	Output is correct
14	Correct	1 ms	736 KB	Output is correct
15	Correct	1 ms	468 KB	Output is correct
16	Correct	0 ms	468 KB	Output is correct
17	Correct	0 ms	468 KB	Output is correct
18	Correct	0 ms	468 KB	Output is correct
19	Correct	1 ms	592 KB	Output is correct
20	Correct	1 ms	468 KB	Output is correct
21	Correct	1 ms	596 KB	Output is correct
22	Correct	1 ms	596 KB	Output is correct
23	Correct	1 ms	596 KB	Output is correct
24	Correct	1 ms	596 KB	Output is correct
25	Correct	1 ms	724 KB	Output is correct
26	Correct	1 ms	772 KB	Output is correct
27	Correct	1 ms	724 KB	Output is correct
28	Correct	1 ms	724 KB	Output is correct
29	Correct	1 ms	724 KB	Output is correct
30	Correct	1 ms	724 KB	Output is correct
31	Correct	1 ms	852 KB	Output is correct
32	Correct	1 ms	852 KB	Output is correct
33	Correct	8 ms	2644 KB	Output is correct
34	Correct	10 ms	2896 KB	Output is correct
35	Correct	22 ms	2644 KB	Output is correct
36	Correct	10 ms	3028 KB	Output is correct
37	Correct	10 ms	3028 KB	Output is correct
38	Correct	33 ms	3028 KB	Output is correct
39	Correct	13 ms	3412 KB	Output is correct
40	Correct	13 ms	3496 KB	Output is correct
41	Correct	41 ms	3412 KB	Output is correct
42	Correct	15 ms	3876 KB	Output is correct
43	Correct	15 ms	3796 KB	Output is correct
44	Correct	52 ms	3864 KB	Output is correct
45	Correct	19 ms	4180 KB	Output is correct
46	Correct	19 ms	4304 KB	Output is correct
47	Correct	60 ms	4180 KB	Output is correct
48	Correct	21 ms	4688 KB	Output is correct
49	Correct	23 ms	4564 KB	Output is correct
50	Correct	73 ms	4632 KB	Output is correct
51	Correct	25 ms	4948 KB	Output is correct
52	Correct	26 ms	4948 KB	Output is correct
53	Correct	85 ms	4948 KB	Output is correct
54	Correct	30 ms	5384 KB	Output is correct
55	Correct	30 ms	5332 KB	Output is correct
56	Correct	100 ms	5332 KB	Output is correct
57	Correct	33 ms	5716 KB	Output is correct
58	Correct	35 ms	5716 KB	Output is correct
59	Correct	122 ms	5820 KB	Output is correct
60	Correct	38 ms	6204 KB	Output is correct
61	Correct	40 ms	6100 KB	Output is correct
62	Correct	155 ms	6208 KB	Output is correct
63	Correct	126 ms	6200 KB	Output is correct
64	Correct	210 ms	6100 KB	Output is correct
65	Correct	206 ms	6204 KB	Output is correct
66	Correct	145 ms	6200 KB	Output is correct
67	Correct	133 ms	6100 KB	Output is correct
68	Correct	49 ms	6228 KB	Output is correct
69	Correct	41 ms	6220 KB	Output is correct
70	Correct	39 ms	6256 KB	Output is correct
71	Correct	31 ms	6228 KB	Output is correct
72	Correct	32 ms	6228 KB	Output is correct
73	Correct	38 ms	6484 KB	Output is correct
74	Correct	70 ms	6480 KB	Output is correct
75	Correct	75 ms	6464 KB	Output is correct
76	Correct	79 ms	6484 KB	Output is correct
77	Correct	77 ms	6484 KB	Output is correct
78	Correct	83 ms	6456 KB	Output is correct
79	Correct	64 ms	6356 KB	Output is correct
80	Correct	82 ms	6540 KB	Output is correct
81	Correct	76 ms	6452 KB	Output is correct
82	Correct	76 ms	6452 KB	Output is correct
83	Correct	91 ms	6416 KB	Output is correct
84	Correct	74 ms	6420 KB	Output is correct
85	Correct	77 ms	6356 KB	Output is correct
86	Correct	88 ms	6392 KB	Output is correct
87	Correct	78 ms	6356 KB	Output is correct
88	Correct	94 ms	6356 KB	Output is correct
89	Correct	95 ms	6476 KB	Output is correct
90	Correct	98 ms	6356 KB	Output is correct
91	Correct	98 ms	6364 KB	Output is correct
92	Correct	102 ms	6356 KB	Output is correct