Submission #484138

# Submission time Handle Problem Language Result Execution time Memory
484138 2021-11-02T07:37:12 Z nehasane Mecho (IOI09_mecho) C++14
42 / 100
427 ms 10828 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], eating_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;
}
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));
        //move bees
        for (auto i : hives)
            bees_q.push({i.first, i.second});
        while (!bees_q.empty()){
            int x = bees_q.front().first, y = bees_q.front().second;
            bees_q.pop();
            for (int i = 0; i < 4; i++){
                int nx = x + dx[i], ny = y + dy[i];
                if (valid_sq(nx, ny) && !bees_visited[nx][ny]){
                    if (eating_dis[x][y] < eating_time){
                        eating_dis[nx][ny] = eating_dis[x][y] + 1;
                    }else{
                        bees_dis[nx][ny] = bees_dis[x][y] + 1;
                        eating_dis[nx][ny] = INT_MAX;
                    }
                    bees_q.push({nx, ny});
                    bees_visited[nx][ny] = true;
                }
            }
        }
        mecho_q.push({startx, starty});
        while (!mecho_q.empty()){
            int x = mecho_q.front().first, y = mecho_q.front().second;
            mecho_q.pop();
            for (int i = 0; i < 4; i++){
                int nx = x + dx[i], ny = y + dy[i];
                if (valid_sq(nx, ny) && !mecho_visited[nx][ny] && (mecho_dis[x][y] + 1) / s < bees_dis[nx][ny]){
                    mecho_visited[nx][ny] = true;
                    mecho_q.push({nx, ny});
                    mecho_dis[nx][ny] = mecho_dis[x][y] + 1;
                }
            }
        }
        bool mecho_reached = false;
        for (int i = 0; i < 4; i++){
            int nx = home_x+ dx[i], ny = home_y + dy[i];
            if (valid_sq(nx, ny)){
                if (bees_dis[nx][ny] > (mecho_dis[nx][ny] / s) && mecho_visited[nx][ny]){
                    mecho_reached = true;
                    break;
                }
            }
        }
        if (mecho_reached)
            l = eating_time + 1;
        else
            r = eating_time - 1;
        }
    cout << l - 1 << '\n';
}

Compilation message

mecho.cpp: In function 'int main()':
mecho.cpp:81:37: warning: 'home_y' may be used uninitialized in this function [-Wmaybe-uninitialized]
   81 |             int nx = home_x+ dx[i], ny = home_y + dy[i];
      |                                     ^~
mecho.cpp:81:17: warning: 'home_x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   81 |             int nx = home_x+ dx[i], ny = home_y + dy[i];
      |                 ^~
# Verdict Execution time Memory Grader output
1 Correct 4 ms 6604 KB Output is correct
2 Correct 4 ms 6604 KB Output is correct
3 Correct 4 ms 6604 KB Output is correct
4 Correct 5 ms 6604 KB Output is correct
5 Correct 4 ms 6604 KB Output is correct
6 Correct 4 ms 6604 KB Output is correct
7 Correct 359 ms 10576 KB Output is correct
8 Correct 4 ms 6604 KB Output is correct
9 Correct 4 ms 6604 KB Output is correct
10 Correct 4 ms 6604 KB Output is correct
11 Correct 4 ms 6600 KB Output is correct
12 Incorrect 6 ms 6732 KB Output isn't correct
13 Incorrect 5 ms 6732 KB Output isn't correct
14 Correct 6 ms 6732 KB Output is correct
15 Incorrect 5 ms 6604 KB Output isn't correct
16 Incorrect 5 ms 6604 KB Output isn't correct
17 Incorrect 7 ms 6604 KB Output isn't correct
18 Incorrect 5 ms 6604 KB Output isn't correct
19 Incorrect 6 ms 6728 KB Output isn't correct
20 Incorrect 6 ms 6604 KB Output isn't correct
21 Incorrect 6 ms 6604 KB Output isn't correct
22 Incorrect 5 ms 6624 KB Output isn't correct
23 Incorrect 6 ms 6732 KB Output isn't correct
24 Incorrect 5 ms 6732 KB Output isn't correct
25 Incorrect 6 ms 6732 KB Output isn't correct
26 Incorrect 6 ms 6732 KB Output isn't correct
27 Incorrect 6 ms 6732 KB Output isn't correct
28 Incorrect 7 ms 6732 KB Output isn't correct
29 Incorrect 6 ms 6732 KB Output isn't correct
30 Incorrect 8 ms 6732 KB Output isn't correct
31 Incorrect 7 ms 6732 KB Output isn't correct
32 Incorrect 8 ms 6732 KB Output isn't correct
33 Incorrect 38 ms 7884 KB Output isn't correct
34 Incorrect 44 ms 7956 KB Output isn't correct
35 Correct 52 ms 7884 KB Output is correct
36 Incorrect 50 ms 8112 KB Output isn't correct
37 Incorrect 55 ms 8148 KB Output isn't correct
38 Correct 75 ms 8140 KB Output is correct
39 Incorrect 55 ms 8396 KB Output isn't correct
40 Incorrect 64 ms 8392 KB Output isn't correct
41 Correct 120 ms 8516 KB Output is correct
42 Incorrect 75 ms 8960 KB Output isn't correct
43 Incorrect 88 ms 8840 KB Output isn't correct
44 Correct 113 ms 8812 KB Output is correct
45 Incorrect 84 ms 9088 KB Output isn't correct
46 Incorrect 101 ms 9028 KB Output isn't correct
47 Correct 148 ms 9036 KB Output is correct
48 Incorrect 97 ms 9320 KB Output isn't correct
49 Incorrect 116 ms 9372 KB Output isn't correct
50 Correct 160 ms 9292 KB Output is correct
51 Incorrect 123 ms 9640 KB Output isn't correct
52 Incorrect 142 ms 9640 KB Output isn't correct
53 Correct 196 ms 9648 KB Output is correct
54 Incorrect 132 ms 9804 KB Output isn't correct
55 Incorrect 159 ms 9912 KB Output isn't correct
56 Correct 246 ms 9924 KB Output is correct
57 Incorrect 147 ms 10180 KB Output isn't correct
58 Incorrect 185 ms 10180 KB Output isn't correct
59 Correct 291 ms 10200 KB Output is correct
60 Incorrect 172 ms 10468 KB Output isn't correct
61 Incorrect 208 ms 10412 KB Output isn't correct
62 Correct 361 ms 10700 KB Output is correct
63 Correct 355 ms 10472 KB Output is correct
64 Correct 427 ms 10436 KB Output is correct
65 Correct 417 ms 10444 KB Output is correct
66 Correct 364 ms 10468 KB Output is correct
67 Correct 342 ms 10476 KB Output is correct
68 Correct 333 ms 10496 KB Output is correct
69 Correct 327 ms 10444 KB Output is correct
70 Correct 315 ms 10564 KB Output is correct
71 Correct 323 ms 10616 KB Output is correct
72 Incorrect 303 ms 10496 KB Output isn't correct
73 Incorrect 304 ms 10828 KB Output isn't correct
74 Correct 347 ms 10764 KB Output is correct
75 Correct 329 ms 10700 KB Output is correct
76 Correct 325 ms 10700 KB Output is correct
77 Correct 308 ms 10692 KB Output is correct
78 Correct 314 ms 10804 KB Output is correct
79 Correct 307 ms 10728 KB Output is correct
80 Correct 301 ms 10724 KB Output is correct
81 Correct 339 ms 10692 KB Output is correct
82 Correct 307 ms 10636 KB Output is correct
83 Correct 358 ms 10752 KB Output is correct
84 Correct 324 ms 10692 KB Output is correct
85 Correct 345 ms 10808 KB Output is correct
86 Correct 343 ms 10684 KB Output is correct
87 Correct 337 ms 10692 KB Output is correct
88 Correct 342 ms 10656 KB Output is correct
89 Correct 356 ms 10636 KB Output is correct
90 Correct 339 ms 10564 KB Output is correct
91 Correct 350 ms 10564 KB Output is correct
92 Correct 310 ms 10636 KB Output is correct