Submission #489346

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
489346	2021-11-22T16:56:35 Z	Alexandruabcde	Mecho (IOI09_mecho)	C++14	100 / 100	550 ms	4056 KB

mecho

#include <bits/stdc++.h>

using namespace std;

constexpr int NMAX = 805;
typedef pair <int, int> PII;

int N, S;
char init[NMAX][NMAX];
int viz[NMAX][NMAX];

int dx[] = {1, -1, 0, 0};
int dy[] = {0, 0, 1, -1};

void Read () {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    cin >> N >> S;

    for (int i = 1; i <= N; ++ i )
        for (int j = 1; j <= N; ++ j )
            cin >> init[i][j];
}

bool Interior (int x, int y) {
    return 0 < x && x < N+1 && 0 < y && y < N+1;
}

void Expand (queue <PII> &Bees) {
    queue <PII> next;

    while (!Bees.empty()) {
        PII P = Bees.front();
        Bees.pop();

        for (int i = 0; i < 4; ++ i ) {
            PII urm = {P.first + dx[i], P.second + dy[i]};

            if (Interior(urm.first, urm.second) && (init[urm.first][urm.second] == 'G' || init[urm.first][urm.second] == 'M') && viz[urm.first][urm.second] != -1) {
                next.push(urm);
                viz[urm.first][urm.second] = -1;
            }
        }
    }

    Bees = next;
}

bool Check (int wait) {
    queue <PII> Ends, CanExp;
    PII finish;

    for (int i = 1; i <= N; ++ i ) {
        for (int j = 1; j <= N; ++ j ) {
            if (init[i][j] == 'T') viz[i][j] = -1;

            if (init[i][j] == 'G') viz[i][j] = 0;

            if (init[i][j] == 'M') {
                Ends.push({i, j});
                viz[i][j] = 1;
            }

            if (init[i][j] == 'D') {
                finish = {i, j};
                viz[i][j] = 0;
            }

            if (init[i][j] == 'H') {
                CanExp.push({i, j});
                viz[i][j] = -1;
            }
        }
    }

    for (int i = 1; i <= wait; ++ i )
        Expand(CanExp);

    bool finished = 0;
    while (!finished && !Ends.empty()) {
        for (int pas = 1; pas <= S; ++ pas ) {
            queue <PII> nextEnds;
            while (!Ends.empty()) {
                PII P = Ends.front();
                Ends.pop();

                if (viz[P.first][P.second] != 1) continue;

                for (int i = 0; i < 4; ++ i ) {
                    PII urm = {P.first + dx[i], P.second + dy[i]};

                    if (Interior(urm.first, urm.second) && viz[urm.first][urm.second] == 0) {
                        nextEnds.push(urm);
                        viz[urm.first][urm.second] = 1;
                    }
                }
            }

            Ends = nextEnds;
        }

        if (viz[finish.first][finish.second]) finished = 1;
        Expand(CanExp);
    }

    return finished;
}

int aux[NMAX][NMAX];
int FindRight () {
    queue <PII> Q;
    for (int i = 1; i <= N; ++ i )
        for (int j = 1; j <= N; ++ j ) {
            aux[i][j] = 0;

            if (init[i][j] == 'H') {
                Q.push({i, j});
                aux[i][j] = 1;
            }
        }

    while (!Q.empty()) {
        PII x = Q.front();
        Q.pop();

        for (int i = 0; i < 4; ++ i ) {
            PII urm = {x.first + dx[i], x.second + dy[i]};

            if (Interior(urm.first, urm.second) && aux[urm.first][urm.second] == 0){
                aux[urm.first][urm.second] = aux[x.first][x.second]+1;
                Q.push(urm);
            }
        }
    }

    for (int i = 1; i <= N; ++ i )
        for (int j = 1; j <= N; ++ j )
            if (init[i][j] == 'M') return (aux[i][j] == 0 ? N*N : aux[i][j]);
}

void Solve () {
    int st = 0, dr = N*N;
    int ans = -1;

    while (st <= dr) {
        int mij = (st + dr) / 2;

        if (Check(mij)) {
            ans = mij;
            st = mij + 1;
        }
        else dr = mij - 1;
    }

    cout << ans << '\n';
}

int main () {
    Read();
    Solve();

    return 0;
}

Compilation message

mecho.cpp: In function 'int FindRight()':
mecho.cpp:112:17: warning: control reaches end of non-void function [-Wreturn-type]
  112 |     queue <PII> Q;
      |                 ^

Subtask #1

100.0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	332 KB	Output is correct
2	Correct	0 ms	332 KB	Output is correct
3	Correct	1 ms	332 KB	Output is correct
4	Correct	0 ms	332 KB	Output is correct
5	Correct	0 ms	332 KB	Output is correct
6	Correct	0 ms	332 KB	Output is correct
7	Correct	339 ms	3676 KB	Output is correct
8	Correct	0 ms	332 KB	Output is correct
9	Correct	1 ms	332 KB	Output is correct
10	Correct	0 ms	332 KB	Output is correct
11	Correct	1 ms	332 KB	Output is correct
12	Correct	1 ms	460 KB	Output is correct
13	Correct	1 ms	460 KB	Output is correct
14	Correct	3 ms	460 KB	Output is correct
15	Correct	1 ms	332 KB	Output is correct
16	Correct	1 ms	332 KB	Output is correct
17	Correct	0 ms	332 KB	Output is correct
18	Correct	1 ms	332 KB	Output is correct
19	Correct	1 ms	332 KB	Output is correct
20	Correct	1 ms	332 KB	Output is correct
21	Correct	1 ms	460 KB	Output is correct
22	Correct	1 ms	460 KB	Output is correct
23	Correct	2 ms	460 KB	Output is correct
24	Correct	1 ms	460 KB	Output is correct
25	Correct	2 ms	460 KB	Output is correct
26	Correct	2 ms	460 KB	Output is correct
27	Correct	2 ms	588 KB	Output is correct
28	Correct	2 ms	460 KB	Output is correct
29	Correct	3 ms	588 KB	Output is correct
30	Correct	3 ms	588 KB	Output is correct
31	Correct	4 ms	628 KB	Output is correct
32	Correct	2 ms	588 KB	Output is correct
33	Correct	84 ms	1612 KB	Output is correct
34	Correct	60 ms	1684 KB	Output is correct
35	Correct	44 ms	1696 KB	Output is correct
36	Correct	132 ms	1900 KB	Output is correct
37	Correct	75 ms	1868 KB	Output is correct
38	Correct	68 ms	1892 KB	Output is correct
39	Correct	169 ms	2100 KB	Output is correct
40	Correct	97 ms	1996 KB	Output is correct
41	Correct	74 ms	1996 KB	Output is correct
42	Correct	179 ms	2292 KB	Output is correct
43	Correct	133 ms	2280 KB	Output is correct
44	Correct	89 ms	2284 KB	Output is correct
45	Correct	229 ms	2500 KB	Output is correct
46	Correct	168 ms	2484 KB	Output is correct
47	Correct	116 ms	2488 KB	Output is correct
48	Correct	268 ms	2676 KB	Output is correct
49	Correct	183 ms	2672 KB	Output is correct
50	Correct	128 ms	2688 KB	Output is correct
51	Correct	328 ms	2884 KB	Output is correct
52	Correct	247 ms	2868 KB	Output is correct
53	Correct	152 ms	2892 KB	Output is correct
54	Correct	388 ms	3068 KB	Output is correct
55	Correct	248 ms	3068 KB	Output is correct
56	Correct	190 ms	3080 KB	Output is correct
57	Correct	440 ms	3264 KB	Output is correct
58	Correct	325 ms	3276 KB	Output is correct
59	Correct	200 ms	3276 KB	Output is correct
60	Correct	550 ms	3588 KB	Output is correct
61	Correct	313 ms	3404 KB	Output is correct
62	Correct	234 ms	3396 KB	Output is correct
63	Correct	362 ms	3476 KB	Output is correct
64	Correct	387 ms	3464 KB	Output is correct
65	Correct	345 ms	3460 KB	Output is correct
66	Correct	351 ms	3460 KB	Output is correct
67	Correct	367 ms	3524 KB	Output is correct
68	Correct	388 ms	3516 KB	Output is correct
69	Correct	357 ms	3532 KB	Output is correct
70	Correct	371 ms	3532 KB	Output is correct
71	Correct	439 ms	3532 KB	Output is correct
72	Correct	429 ms	3532 KB	Output is correct
73	Correct	364 ms	4024 KB	Output is correct
74	Correct	346 ms	4012 KB	Output is correct
75	Correct	362 ms	4052 KB	Output is correct
76	Correct	344 ms	4016 KB	Output is correct
77	Correct	348 ms	4020 KB	Output is correct
78	Correct	359 ms	4000 KB	Output is correct
79	Correct	348 ms	3956 KB	Output is correct
80	Correct	400 ms	4056 KB	Output is correct
81	Correct	352 ms	3940 KB	Output is correct
82	Correct	421 ms	3988 KB	Output is correct
83	Correct	374 ms	3880 KB	Output is correct
84	Correct	395 ms	3948 KB	Output is correct
85	Correct	377 ms	3868 KB	Output is correct
86	Correct	370 ms	3944 KB	Output is correct
87	Correct	349 ms	3868 KB	Output is correct
88	Correct	345 ms	3872 KB	Output is correct
89	Correct	349 ms	3788 KB	Output is correct
90	Correct	348 ms	3788 KB	Output is correct
91	Correct	356 ms	3828 KB	Output is correct
92	Correct	403 ms	3788 KB	Output is correct