Submission #484069

# Submission time Handle Problem Language Result Execution time Memory
484069 2021-11-02T04:58:16 Z nehasane Mecho (IOI09_mecho) C++14
12 / 100
234 ms 7636 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]){
    while (!q.empty() && dis[q.front().first][q.front().second] != -1){
        int x = q.front().first, y = q.front().second;
        q.pop();
        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 - 2;
    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;
        }
        update_field(bees_q, eating_time, bees_visited, bees_visited, bees_dis);
        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);
            if (mecho_visited[home_x][home_y])
                break;
            update_field(bees_q, 1, bees_visited, bees_visited, bees_dis);
        }

        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();
    }
    if (r == -1)
        r = 0;
    cout << r << '\n';
}

Compilation message

mecho.cpp: In function 'int main()':
mecho.cpp:85:41: warning: 'home_y' may be used uninitialized in this function [-Wmaybe-uninitialized]
   85 |         if (mecho_visited[home_x][home_y])
      |             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
mecho.cpp:85:41: warning: 'home_x' may be used uninitialized in this function [-Wmaybe-uninitialized]
# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 6476 KB Output isn't correct
2 Incorrect 3 ms 6476 KB Output isn't correct
3 Incorrect 4 ms 6476 KB Output isn't correct
4 Incorrect 3 ms 6476 KB Output isn't correct
5 Correct 4 ms 6580 KB Output is correct
6 Incorrect 3 ms 6476 KB Output isn't correct
7 Incorrect 177 ms 7352 KB Output isn't correct
8 Incorrect 4 ms 6476 KB Output isn't correct
9 Correct 4 ms 6476 KB Output is correct
10 Correct 5 ms 6476 KB Output is correct
11 Correct 5 ms 6476 KB Output is correct
12 Incorrect 5 ms 6604 KB Output isn't correct
13 Incorrect 5 ms 6476 KB Output isn't correct
14 Incorrect 5 ms 6476 KB Output isn't correct
15 Incorrect 4 ms 6476 KB Output isn't correct
16 Incorrect 4 ms 6476 KB Output isn't correct
17 Incorrect 4 ms 6476 KB Output isn't correct
18 Incorrect 4 ms 6476 KB Output isn't correct
19 Incorrect 4 ms 6476 KB Output isn't correct
20 Incorrect 4 ms 6476 KB Output isn't correct
21 Incorrect 4 ms 6476 KB Output isn't correct
22 Incorrect 4 ms 6476 KB Output isn't correct
23 Incorrect 4 ms 6476 KB Output isn't correct
24 Incorrect 5 ms 6476 KB Output isn't correct
25 Incorrect 5 ms 6476 KB Output isn't correct
26 Incorrect 6 ms 6476 KB Output isn't correct
27 Incorrect 5 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 5 ms 6476 KB Output isn't correct
31 Incorrect 7 ms 6476 KB Output isn't correct
32 Incorrect 5 ms 6604 KB Output isn't correct
33 Incorrect 9 ms 6752 KB Output isn't correct
34 Incorrect 10 ms 6732 KB Output isn't correct
35 Correct 23 ms 6732 KB Output is correct
36 Incorrect 8 ms 6732 KB Output isn't correct
37 Incorrect 12 ms 6744 KB Output isn't correct
38 Correct 32 ms 6760 KB Output is correct
39 Incorrect 9 ms 6684 KB Output isn't correct
40 Incorrect 9 ms 6732 KB Output isn't correct
41 Correct 44 ms 6800 KB Output is correct
42 Incorrect 10 ms 6944 KB Output isn't correct
43 Incorrect 11 ms 6988 KB Output isn't correct
44 Correct 48 ms 7056 KB Output is correct
45 Incorrect 12 ms 7104 KB Output isn't correct
46 Incorrect 12 ms 7104 KB Output isn't correct
47 Correct 70 ms 7108 KB Output is correct
48 Incorrect 13 ms 7152 KB Output isn't correct
49 Incorrect 20 ms 7156 KB Output isn't correct
50 Correct 73 ms 7160 KB Output is correct
51 Incorrect 15 ms 7116 KB Output isn't correct
52 Incorrect 15 ms 7104 KB Output isn't correct
53 Correct 76 ms 7204 KB Output is correct
54 Incorrect 16 ms 7244 KB Output isn't correct
55 Incorrect 17 ms 7140 KB Output isn't correct
56 Correct 112 ms 7244 KB Output is correct
57 Incorrect 19 ms 7296 KB Output isn't correct
58 Incorrect 18 ms 7204 KB Output isn't correct
59 Correct 116 ms 7232 KB Output is correct
60 Incorrect 18 ms 7244 KB Output isn't correct
61 Incorrect 20 ms 7244 KB Output isn't correct
62 Correct 136 ms 7336 KB Output is correct
63 Correct 175 ms 7352 KB Output is correct
64 Correct 157 ms 7336 KB Output is correct
65 Correct 183 ms 7236 KB Output is correct
66 Incorrect 223 ms 7340 KB Output isn't correct
67 Incorrect 187 ms 7284 KB Output isn't correct
68 Correct 168 ms 7368 KB Output is correct
69 Correct 140 ms 7372 KB Output is correct
70 Correct 201 ms 7480 KB Output is correct
71 Correct 179 ms 7372 KB Output is correct
72 Incorrect 220 ms 7364 KB Output isn't correct
73 Incorrect 133 ms 7628 KB Output isn't correct
74 Correct 203 ms 7624 KB Output is correct
75 Correct 234 ms 7628 KB Output is correct
76 Correct 226 ms 7636 KB Output is correct
77 Correct 221 ms 7628 KB Output is correct
78 Incorrect 198 ms 7556 KB Output isn't correct
79 Correct 186 ms 7492 KB Output is correct
80 Correct 190 ms 7608 KB Output is correct
81 Correct 207 ms 7500 KB Output is correct
82 Correct 199 ms 7592 KB Output is correct
83 Correct 216 ms 7560 KB Output is correct
84 Correct 188 ms 7556 KB Output is correct
85 Correct 212 ms 7548 KB Output is correct
86 Correct 223 ms 7556 KB Output is correct
87 Correct 191 ms 7552 KB Output is correct
88 Correct 197 ms 7500 KB Output is correct
89 Correct 212 ms 7540 KB Output is correct
90 Correct 189 ms 7432 KB Output is correct
91 Correct 202 ms 7468 KB Output is correct
92 Correct 180 ms 7500 KB Output is correct