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Submission #484153

# Submission time Handle Problem Language Result Execution time Memory
484153 2021-11-02T08:16:29 Z nehasane Mecho (IOI09_mecho) C++14
89 / 100
 617 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;
        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:74:39: warning: 'starty' may be used uninitialized in this function [-Wmaybe-uninitialized]
   74 |         mecho_visited[startx][starty] = true;
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
mecho.cpp:74:39: warning: 'startx' may be used uninitialized in this function [-Wmaybe-uninitialized]
mecho.cpp:89:37: warning: 'home_y' may be used uninitialized in this function [-Wmaybe-uninitialized]
   89 |             int nx = home_x+ dx[i], ny = home_y + dy[i];
      |                                     ^~
mecho.cpp:89:17: warning: 'home_x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   89 |             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 4 ms 6476 KB Output is correct
2 Correct 4 ms 6604 KB Output is correct
3 Correct 3 ms 6476 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 502 ms 9920 KB Output is correct
8 Correct 4 ms 6604 KB Output is correct
9 Correct 5 ms 6604 KB Output is correct
10 Correct 5 ms 6604 KB Output is correct
11 Correct 4 ms 6604 KB Output is correct
12 Correct 6 ms 6732 KB Output is correct
13 Incorrect 7 ms 6744 KB Output isn't correct
14 Correct 8 ms 6780 KB Output is correct
15 Correct 5 ms 6604 KB Output is correct
16 Correct 5 ms 6604 KB Output is correct
17 Correct 6 ms 6732 KB Output is correct
18 Correct 5 ms 6604 KB Output is correct
19 Correct 5 ms 6604 KB Output is correct
20 Correct 5 ms 6604 KB Output is correct
21 Correct 5 ms 6604 KB Output is correct
22 Correct 6 ms 6604 KB Output is correct
23 Correct 5 ms 6732 KB Output is correct
24 Correct 5 ms 6732 KB Output is correct
25 Correct 5 ms 6732 KB Output is correct
26 Correct 8 ms 6860 KB Output is correct
27 Correct 7 ms 6732 KB Output is correct
28 Correct 8 ms 6732 KB Output is correct
29 Correct 8 ms 6732 KB Output is correct
30 Correct 7 ms 6732 KB Output is correct
31 Correct 6 ms 6828 KB Output is correct
32 Correct 7 ms 6732 KB Output is correct
33 Correct 45 ms 7756 KB Output is correct
34 Correct 39 ms 7756 KB Output is correct
35 Correct 90 ms 7868 KB Output is correct
36 Correct 50 ms 8012 KB Output is correct
37 Correct 51 ms 8004 KB Output is correct
38 Correct 95 ms 8012 KB Output is correct
39 Correct 62 ms 8188 KB Output is correct
40 Correct 67 ms 8192 KB Output is correct
41 Correct 132 ms 8212 KB Output is correct
42 Correct 77 ms 8524 KB Output is correct
43 Correct 92 ms 8536 KB Output is correct
44 Correct 157 ms 8560 KB Output is correct
45 Correct 101 ms 8780 KB Output is correct
46 Correct 92 ms 8900 KB Output is correct
47 Correct 184 ms 8824 KB Output is correct
48 Correct 107 ms 9092 KB Output is correct
49 Correct 108 ms 9036 KB Output is correct
50 Correct 238 ms 9152 KB Output is correct
51 Correct 131 ms 9204 KB Output is correct
52 Correct 129 ms 9164 KB Output is correct
53 Correct 288 ms 9236 KB Output is correct
54 Correct 175 ms 9420 KB Output is correct
55 Correct 151 ms 9328 KB Output is correct
56 Correct 337 ms 9420 KB Output is correct
57 Correct 172 ms 9640 KB Output is correct
58 Correct 165 ms 9548 KB Output is correct
59 Correct 384 ms 9640 KB Output is correct
60 Correct 200 ms 9804 KB Output is correct
61 Correct 187 ms 9752 KB Output is correct
62 Correct 450 ms 9856 KB Output is correct
63 Correct 496 ms 9804 KB Output is correct
64 Correct 617 ms 9924 KB Output is correct
65 Correct 556 ms 9844 KB Output is correct
66 Correct 521 ms 9804 KB Output is correct
67 Correct 509 ms 9848 KB Output is correct
68 Correct 477 ms 9804 KB Output is correct
69 Correct 492 ms 9924 KB Output is correct
70 Correct 489 ms 9936 KB Output is correct
71 Correct 492 ms 9876 KB Output is correct
72 Incorrect 471 ms 9872 KB Output isn't correct
73 Incorrect 453 ms 10148 KB Output isn't correct
74 Correct 466 ms 10180 KB Output is correct
75 Correct 539 ms 10232 KB Output is correct
76 Correct 486 ms 10136 KB Output is correct
77 Correct 482 ms 10188 KB Output is correct
78 Correct 501 ms 10176 KB Output is correct
79 Correct 483 ms 10100 KB Output is correct
80 Correct 482 ms 10040 KB Output is correct
81 Correct 494 ms 10100 KB Output is correct
82 Correct 542 ms 10112 KB Output is correct
83 Correct 510 ms 10180 KB Output is correct
84 Correct 481 ms 10068 KB Output is correct
85 Correct 536 ms 10052 KB Output is correct
86 Correct 499 ms 10060 KB Output is correct
87 Correct 496 ms 10180 KB Output is correct
88 Correct 505 ms 10052 KB Output is correct
89 Correct 491 ms 9932 KB Output is correct
90 Correct 508 ms 10000 KB Output is correct
91 Correct 499 ms 9932 KB Output is correct
92 Correct 529 ms 10004 KB Output is correct