Submission #484085

# Submission time Handle Problem Language Result Execution time Memory
484085 2021-11-02T05:33:58 Z nehasane Mecho (IOI09_mecho) C++14
39 / 100
258 ms 7676 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 && 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 = 2*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 3 ms 6476 KB Output isn't correct
3 Correct 3 ms 6476 KB Output is correct
4 Incorrect 3 ms 6476 KB Output isn't correct
5 Correct 3 ms 6492 KB Output is correct
6 Incorrect 4 ms 6476 KB Output isn't correct
7 Incorrect 219 ms 7440 KB Output isn't correct
8 Correct 4 ms 6476 KB Output is correct
9 Correct 4 ms 6476 KB Output is correct
10 Correct 4 ms 6476 KB Output is correct
11 Correct 4 ms 6508 KB Output is correct
12 Incorrect 4 ms 6476 KB Output isn't correct
13 Correct 5 ms 6476 KB Output is correct
14 Correct 5 ms 6588 KB Output is 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 6580 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 6 ms 6476 KB Output isn't correct
22 Incorrect 6 ms 6476 KB Output isn't correct
23 Incorrect 5 ms 6476 KB Output isn't correct
24 Incorrect 4 ms 6476 KB Output isn't correct
25 Incorrect 4 ms 6476 KB Output isn't correct
26 Incorrect 4 ms 6476 KB Output isn't correct
27 Incorrect 5 ms 6476 KB Output isn't correct
28 Incorrect 4 ms 6476 KB Output isn't correct
29 Incorrect 5 ms 6584 KB Output isn't correct
30 Incorrect 4 ms 6476 KB Output isn't correct
31 Incorrect 4 ms 6476 KB Output isn't correct
32 Incorrect 5 ms 6584 KB Output isn't correct
33 Incorrect 8 ms 6752 KB Output isn't correct
34 Incorrect 8 ms 6732 KB Output isn't correct
35 Correct 29 ms 6732 KB Output is correct
36 Incorrect 9 ms 6732 KB Output isn't correct
37 Incorrect 9 ms 6744 KB Output isn't correct
38 Correct 39 ms 6732 KB Output is correct
39 Incorrect 9 ms 6732 KB Output isn't correct
40 Incorrect 10 ms 6712 KB Output isn't correct
41 Correct 52 ms 6748 KB Output is correct
42 Incorrect 10 ms 6988 KB Output isn't correct
43 Incorrect 11 ms 7044 KB Output isn't correct
44 Correct 60 ms 6988 KB Output is correct
45 Incorrect 12 ms 7100 KB Output isn't correct
46 Incorrect 12 ms 6988 KB Output isn't correct
47 Correct 69 ms 7104 KB Output is correct
48 Incorrect 13 ms 7116 KB Output isn't correct
49 Incorrect 15 ms 7080 KB Output isn't correct
50 Correct 81 ms 7040 KB Output is correct
51 Incorrect 15 ms 7188 KB Output isn't correct
52 Incorrect 15 ms 7136 KB Output isn't correct
53 Correct 106 ms 7244 KB Output is correct
54 Incorrect 19 ms 7244 KB Output isn't correct
55 Incorrect 16 ms 7224 KB Output isn't correct
56 Correct 113 ms 7152 KB Output is correct
57 Incorrect 18 ms 7244 KB Output isn't correct
58 Incorrect 18 ms 7232 KB Output isn't correct
59 Correct 137 ms 7300 KB Output is correct
60 Incorrect 21 ms 7244 KB Output isn't correct
61 Incorrect 26 ms 7288 KB Output isn't correct
62 Correct 164 ms 7372 KB Output is correct
63 Incorrect 194 ms 7340 KB Output isn't correct
64 Correct 177 ms 7244 KB Output is correct
65 Correct 218 ms 7332 KB Output is correct
66 Correct 223 ms 7244 KB Output is correct
67 Correct 213 ms 7332 KB Output is correct
68 Correct 218 ms 7372 KB Output is correct
69 Correct 157 ms 7360 KB Output is correct
70 Correct 197 ms 7372 KB Output is correct
71 Correct 199 ms 7316 KB Output is correct
72 Correct 248 ms 7284 KB Output is correct
73 Correct 174 ms 7628 KB Output is correct
74 Correct 245 ms 7628 KB Output is correct
75 Correct 240 ms 7676 KB Output is correct
76 Correct 257 ms 7628 KB Output is correct
77 Correct 213 ms 7640 KB Output is correct
78 Correct 238 ms 7592 KB Output is correct
79 Correct 223 ms 7500 KB Output is correct
80 Correct 221 ms 7500 KB Output is correct
81 Correct 251 ms 7592 KB Output is correct
82 Correct 236 ms 7500 KB Output is correct
83 Correct 258 ms 7488 KB Output is correct
84 Correct 237 ms 7556 KB Output is correct
85 Correct 236 ms 7556 KB Output is correct
86 Correct 242 ms 7556 KB Output is correct
87 Correct 241 ms 7620 KB Output is correct
88 Correct 258 ms 7500 KB Output is correct
89 Correct 224 ms 7424 KB Output is correct
90 Correct 250 ms 7556 KB Output is correct
91 Correct 225 ms 7508 KB Output is correct
92 Correct 218 ms 7396 KB Output is correct