Submission #484079

# Submission time Handle Problem Language Result Execution time Memory
484079 2021-11-02T05:25:50 Z nehasane Mecho (IOI09_mecho) C++14
28 / 100
380 ms 7748 KB
#include <bits/stdc++.h>
using namespace std;
const int MAX_N = 800;
vector <string> field(MAX_N);
bool bees_visited[MAX_N][MAX_N], mecho_visited[MAX_N][MAX_N];
int mecho_dis[MAX_N][MAX_N], bees_dis[MAX_N][MAX_N];
queue <pair <int, int>> mecho_q, bees_q;
int dx[] = {-1, 1, 0, 0};
int dy[] = {0, 0, -1, 1};
int n, s;
bool valid_sq(int x, int y){
    if (x >= 0 && x < n && y >= 0 && y < n && field[x][y] != 'T' && field[x][y] != 'H')
        return true;
    return false;
}
void update_field(queue <pair <int, int>> &q, int max_steps, bool (&visited)[MAX_N][MAX_N], bool (&visited2)[MAX_N][MAX_N], int (&dis)[MAX_N][MAX_N], bool is_mecho){
    while (!q.empty() && dis[q.front().first][q.front().second] != -1){
        int x = q.front().first, y = q.front().second;
        q.pop();
        if (is_mecho && visited[x][y] && visited2[x][y])
            continue;
        for (int i = 0; i < 4; i++){
            if (valid_sq(x + dx[i], y + dy[i]) && !visited[x+dx[i]][y+dy[i]] && !visited2[x+dx[i]][y+dy[i]]){
                q.push({x+dx[i], y+dy[i]});
                visited[x+dx[i]][y+dy[i]] = true;
                if (dis[x][y] + 1 < max_steps)
                    dis[x+dx[i]][y+dy[i]] = dis[x][y] + 1;
                else
                    dis[x+dx[i]][y+dy[i]] = -1;
            }
        }
    }
}
int main()
{
    // freopen("in.txt", "r", stdin);
    // freopen("out.txt", "w", stdout);
    cin >> n >> s;
    for (int i = 0; i < n; i++)
        cin >> field[i];
    vector <pair <int, int>> hives;
    int startx, starty, home_x, home_y;
    //find Mecho's position
    for (int i = 0; i < n; i++){
        for (int j = 0; j < n; j++){
            if (field[i][j] == 'M'){
                startx = i;
                starty = j;
            }else if (field[i][j] == 'H'){
                hives.push_back({i, j});
            }else if (field[i][j] == 'D'){
                home_x = i;
                home_y = j;
            }
        }
    }
    int l = 0, r = n*n;
    while (l <= r){
        int eating_time = (l + r) / 2;
        memset(bees_visited, false, sizeof(bees_visited));
        memset(mecho_visited, false, sizeof(mecho_visited));
        memset(bees_dis, 0, sizeof(bees_dis));
        memset(mecho_dis, 0, sizeof(mecho_dis));
        //simulate
        for (auto i : hives){
            bees_q.push({i.first, i.second});
            bees_visited[i.first][i.second] = true;
        }
        if (eating_time > 0)
            update_field(bees_q, eating_time, bees_visited, bees_visited, bees_dis, false);
        mecho_q.push({startx, starty});
        for (int i = eating_time; i <= n*2-2 && !bees_q.empty() && !mecho_q.empty(); i++){
            while (!bees_q.empty() && bees_dis[bees_q.front().first][bees_q.front().second] == -1){
                bees_dis[bees_q.front().first][bees_q.front().second] = 0;
                bees_q.push({bees_q.front().first, bees_q.front().second});
                bees_q.pop();
            }while (!mecho_q.empty() && mecho_dis[mecho_q.front().first][mecho_q.front().second] == -1){
                mecho_dis[mecho_q.front().first][mecho_q.front().second] = 0;
                mecho_q.push({mecho_q.front().first, mecho_q.front().second});
                mecho_q.pop();
            }
            update_field(mecho_q, s, mecho_visited, bees_visited, mecho_dis, true);
            if (mecho_visited[home_x][home_y])
                break;
            update_field(bees_q, 1, bees_visited, bees_visited, bees_dis, false);
        }
        if (mecho_visited[home_x][home_y])
            l = eating_time + 1;
        else
            r = eating_time - 1;
        //empty_queues
        while (!bees_q.empty())
            bees_q.pop();
        while (!mecho_q.empty())
            mecho_q.pop();
    }
    cout << r << '\n';
}

Compilation message

mecho.cpp: In function 'int main()':
mecho.cpp:87:41: warning: 'home_y' may be used uninitialized in this function [-Wmaybe-uninitialized]
   87 |         if (mecho_visited[home_x][home_y])
      |             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
mecho.cpp:87:41: warning: 'home_x' may be used uninitialized in this function [-Wmaybe-uninitialized]
# Verdict Execution time Memory Grader output
1 Correct 3 ms 6476 KB Output is correct
2 Incorrect 4 ms 6476 KB Output isn't correct
3 Correct 4 ms 6476 KB Output is correct
4 Incorrect 4 ms 6476 KB Output isn't correct
5 Correct 4 ms 6476 KB Output is correct
6 Incorrect 4 ms 6476 KB Output isn't correct
7 Incorrect 312 ms 7556 KB Output isn't correct
8 Correct 4 ms 6476 KB Output is correct
9 Correct 5 ms 6476 KB Output is correct
10 Correct 4 ms 6476 KB Output is correct
11 Correct 4 ms 6476 KB Output is correct
12 Incorrect 5 ms 6476 KB Output isn't correct
13 Incorrect 6 ms 6476 KB Output isn't correct
14 Correct 6 ms 6476 KB Output is correct
15 Incorrect 5 ms 6476 KB Output isn't correct
16 Incorrect 4 ms 6476 KB Output isn't correct
17 Incorrect 5 ms 6476 KB Output isn't correct
18 Incorrect 5 ms 6476 KB Output isn't correct
19 Incorrect 7 ms 6576 KB Output isn't correct
20 Incorrect 5 ms 6476 KB Output isn't correct
21 Incorrect 5 ms 6476 KB Output isn't correct
22 Incorrect 5 ms 6476 KB Output isn't correct
23 Incorrect 5 ms 6524 KB Output isn't correct
24 Incorrect 5 ms 6476 KB Output isn't correct
25 Incorrect 5 ms 6580 KB Output isn't correct
26 Incorrect 5 ms 6476 KB Output isn't correct
27 Incorrect 6 ms 6476 KB Output isn't correct
28 Incorrect 6 ms 6476 KB Output isn't correct
29 Incorrect 5 ms 6476 KB Output isn't correct
30 Incorrect 6 ms 6476 KB Output isn't correct
31 Incorrect 6 ms 6476 KB Output isn't correct
32 Incorrect 5 ms 6476 KB Output isn't correct
33 Incorrect 12 ms 6732 KB Output isn't correct
34 Incorrect 12 ms 6732 KB Output isn't correct
35 Correct 41 ms 6732 KB Output is correct
36 Incorrect 13 ms 6776 KB Output isn't correct
37 Incorrect 14 ms 6772 KB Output isn't correct
38 Correct 55 ms 6744 KB Output is correct
39 Incorrect 21 ms 6732 KB Output isn't correct
40 Incorrect 21 ms 6732 KB Output isn't correct
41 Correct 70 ms 6732 KB Output is correct
42 Incorrect 17 ms 6988 KB Output isn't correct
43 Incorrect 19 ms 6988 KB Output isn't correct
44 Correct 83 ms 7016 KB Output is correct
45 Incorrect 19 ms 6988 KB Output isn't correct
46 Incorrect 22 ms 6988 KB Output isn't correct
47 Correct 98 ms 6988 KB Output is correct
48 Incorrect 22 ms 7052 KB Output isn't correct
49 Incorrect 28 ms 7148 KB Output isn't correct
50 Correct 116 ms 7236 KB Output is correct
51 Incorrect 24 ms 7212 KB Output isn't correct
52 Incorrect 28 ms 7116 KB Output isn't correct
53 Correct 141 ms 7192 KB Output is correct
54 Incorrect 28 ms 7252 KB Output isn't correct
55 Incorrect 31 ms 7244 KB Output isn't correct
56 Correct 159 ms 7236 KB Output is correct
57 Incorrect 34 ms 7332 KB Output isn't correct
58 Incorrect 34 ms 7244 KB Output isn't correct
59 Correct 183 ms 7300 KB Output is correct
60 Incorrect 34 ms 7244 KB Output isn't correct
61 Incorrect 39 ms 7244 KB Output isn't correct
62 Correct 213 ms 7344 KB Output is correct
63 Incorrect 331 ms 7344 KB Output isn't correct
64 Correct 335 ms 7244 KB Output is correct
65 Correct 315 ms 7364 KB Output is correct
66 Correct 350 ms 7244 KB Output is correct
67 Correct 334 ms 7244 KB Output is correct
68 Correct 339 ms 7372 KB Output is correct
69 Correct 295 ms 7360 KB Output is correct
70 Correct 322 ms 7372 KB Output is correct
71 Correct 362 ms 7360 KB Output is correct
72 Incorrect 380 ms 7372 KB Output isn't correct
73 Incorrect 272 ms 7632 KB Output isn't correct
74 Correct 329 ms 7748 KB Output is correct
75 Correct 357 ms 7556 KB Output is correct
76 Correct 353 ms 7628 KB Output is correct
77 Correct 317 ms 7732 KB Output is correct
78 Correct 334 ms 7484 KB Output is correct
79 Correct 337 ms 7588 KB Output is correct
80 Correct 332 ms 7600 KB Output is correct
81 Correct 332 ms 7620 KB Output is correct
82 Correct 319 ms 7500 KB Output is correct
83 Correct 348 ms 7540 KB Output is correct
84 Correct 330 ms 7564 KB Output is correct
85 Correct 334 ms 7572 KB Output is correct
86 Correct 339 ms 7552 KB Output is correct
87 Correct 319 ms 7532 KB Output is correct
88 Correct 345 ms 7504 KB Output is correct
89 Correct 322 ms 7520 KB Output is correct
90 Correct 318 ms 7500 KB Output is correct
91 Correct 308 ms 7472 KB Output is correct
92 Correct 346 ms 7500 KB Output is correct