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Submission #484158

# Submission time Handle Problem Language Result Execution time Memory
484158 2021-11-02T08:36:13 Z nehasane Mecho (IOI09_mecho) C++14
89 / 100
 659 ms 10232 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, bool is_mecho){
    if (x >= 0 && x < n && y >= 0 && y < n){
        if (is_mecho && (field[x][y] == 'G' || field[x][y] == 'D' || field[x][y] == 'M'))
            return true;
        else if (!is_mecho && (field[x][y] == 'G' || field[x][y] == 'M'))
            return true;
        return false;
    }
    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 = 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));
        //move bees
        for (auto i : hives){
            bees_q.push({i.first, i.second});
            bees_visited[i.first][i.second] = true;
        }
        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, false) && !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});
        mecho_visited[startx][starty] = true;
        if (max(eating_dis[startx][starty], bees_dis[startx][starty]) < eating_time && bees_visited[startx][starty])
            mecho_q.pop();
        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, true) && !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, true)){
                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:75:115: warning: 'starty' may be used uninitialized in this function [-Wmaybe-uninitialized]
   75 |         if (max(eating_dis[startx][starty], bees_dis[startx][starty]) < eating_time && bees_visited[startx][starty])
      |                                                                                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~^
mecho.cpp:75:115: warning: 'startx' may be used uninitialized in this function [-Wmaybe-uninitialized]
mecho.cpp:91:37: warning: 'home_y' may be used uninitialized in this function [-Wmaybe-uninitialized]
   91 |             int nx = home_x+ dx[i], ny = home_y + dy[i];
      |                                     ^~
mecho.cpp:91:17: warning: 'home_x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   91 |             int nx = home_x+ dx[i], ny = home_y + dy[i];
      |                 ^~

Subtask #1
89.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 6476 KB Output is correct
2 Correct 3 ms 6540 KB Output is correct
3 Correct 3 ms 6476 KB Output is correct
4 Correct 3 ms 6600 KB Output is correct
5 Correct 4 ms 6604 KB Output is correct
6 Correct 4 ms 6604 KB Output is correct
7 Correct 547 ms 10072 KB Output is correct
8 Correct 4 ms 6604 KB Output is correct
9 Correct 5 ms 6604 KB Output is correct
10 Correct 4 ms 6604 KB Output is correct
11 Correct 6 ms 6604 KB Output is correct
12 Correct 6 ms 6732 KB Output is correct
13 Incorrect 7 ms 6740 KB Output isn't correct
14 Correct 10 ms 6732 KB Output is correct
15 Correct 5 ms 6604 KB Output is correct
16 Correct 4 ms 6604 KB Output is correct
17 Correct 5 ms 6604 KB Output is correct
18 Correct 5 ms 6604 KB Output is correct
19 Correct 5 ms 6604 KB Output is correct
20 Correct 7 ms 6604 KB Output is correct
21 Correct 6 ms 6604 KB Output is correct
22 Correct 5 ms 6704 KB Output is correct
23 Correct 6 ms 6732 KB Output is correct
24 Correct 7 ms 6732 KB Output is correct
25 Correct 6 ms 6732 KB Output is correct
26 Correct 6 ms 6776 KB Output is correct
27 Correct 9 ms 6732 KB Output is correct
28 Correct 10 ms 6732 KB Output is correct
29 Correct 7 ms 6732 KB Output is correct
30 Correct 8 ms 6732 KB Output is correct
31 Correct 7 ms 6732 KB Output is correct
32 Correct 9 ms 6732 KB Output is correct
33 Correct 44 ms 7796 KB Output is correct
34 Correct 41 ms 7740 KB Output is correct
35 Correct 82 ms 7836 KB Output is correct
36 Correct 54 ms 8012 KB Output is correct
37 Correct 56 ms 8012 KB Output is correct
38 Correct 102 ms 8020 KB Output is correct
39 Correct 87 ms 8144 KB Output is correct
40 Correct 75 ms 8116 KB Output is correct
41 Correct 126 ms 8140 KB Output is correct
42 Correct 83 ms 8604 KB Output is correct
43 Correct 78 ms 8604 KB Output is correct
44 Correct 165 ms 8620 KB Output is correct
45 Correct 97 ms 8780 KB Output is correct
46 Correct 90 ms 8812 KB Output is correct
47 Correct 203 ms 8816 KB Output is correct
48 Correct 109 ms 8908 KB Output is correct
49 Correct 109 ms 9016 KB Output is correct
50 Correct 228 ms 8908 KB Output is correct
51 Correct 138 ms 9284 KB Output is correct
52 Correct 128 ms 9220 KB Output is correct
53 Correct 285 ms 9232 KB Output is correct
54 Correct 155 ms 9412 KB Output is correct
55 Correct 162 ms 9432 KB Output is correct
56 Correct 354 ms 9448 KB Output is correct
57 Correct 170 ms 9544 KB Output is correct
58 Correct 170 ms 9672 KB Output is correct
59 Correct 378 ms 9644 KB Output is correct
60 Correct 195 ms 9836 KB Output is correct
61 Correct 186 ms 9924 KB Output is correct
62 Correct 422 ms 9804 KB Output is correct
63 Correct 504 ms 9972 KB Output is correct
64 Correct 623 ms 9840 KB Output is correct
65 Correct 659 ms 9848 KB Output is correct
66 Correct 556 ms 9836 KB Output is correct
67 Correct 559 ms 9924 KB Output is correct
68 Correct 483 ms 9872 KB Output is correct
69 Correct 520 ms 9920 KB Output is correct
70 Correct 455 ms 9888 KB Output is correct
71 Correct 487 ms 9988 KB Output is correct
72 Incorrect 466 ms 9924 KB Output isn't correct
73 Incorrect 440 ms 10052 KB Output isn't correct
74 Correct 468 ms 10232 KB Output is correct
75 Correct 532 ms 10060 KB Output is correct
76 Correct 482 ms 10180 KB Output is correct
77 Correct 474 ms 10180 KB Output is correct
78 Correct 506 ms 10052 KB Output is correct
79 Correct 478 ms 10100 KB Output is correct
80 Correct 468 ms 10060 KB Output is correct
81 Correct 503 ms 9992 KB Output is correct
82 Correct 521 ms 10064 KB Output is correct
83 Correct 642 ms 9984 KB Output is correct
84 Correct 532 ms 10064 KB Output is correct
85 Correct 545 ms 10064 KB Output is correct
86 Correct 491 ms 10052 KB Output is correct
87 Correct 506 ms 10156 KB Output is correct
88 Correct 513 ms 10008 KB Output is correct
89 Correct 514 ms 10000 KB Output is correct
90 Correct 504 ms 9892 KB Output is correct
91 Correct 497 ms 9932 KB Output is correct
92 Correct 540 ms 10016 KB Output is correct