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Submission #970852

# Submission time Handle Problem Language Result Execution time Memory
970852 2024-04-27T11:32:47 Z Thunnus Mecho (IOI09_mecho) C++17
100 / 100
 262 ms 3080 KB 
#include<bits/stdc++.h>
using namespace std;
using i64 = long long;
#define int i64
#define vi vector<int>
#define vvi vector<vi>
#define vb vector<bool>
#define sz(x) (int)(x).size()
#define pii pair<int,int>
#define fi first
#define se second

const int MAXN = 800;
const int dx[4] = {-1, 0, 1, 0};
const int dy[4] = {0, -1, 0, 1};
int n, s;
vector<string> forest(MAXN);
queue<array<int, 3>> hives;
pii start;

inline bool inside(int x, int y) {return x >= 0 && x < n && y >= 0 && y < n;}

inline bool check(int time){
    vector<string> t_forest = forest;
    queue<array<int, 3>> bees = hives;
    queue<array<int, 3>> frontier;
    vector<vb> vis(vector<vb>(n, vb(n)));
    int minutes = 0;
    while(!bees.empty()){
        array<int, 3> b = bees.front();
        if(b[2] == time)
            break;
        bees.pop();
        for(int i = 0; i < 4; i++){
            int new_x = b[0] + dx[i];
            int new_y = b[1] + dy[i];
            if(inside(new_x, new_y) && (t_forest[new_x][new_y] == 'G' || t_forest[new_x][new_y] == 'M')){
                bees.push({new_x, new_y, b[2] + 1});
                t_forest[new_x][new_y] = 'H';
            }
        }
        if(t_forest[start.fi][start.se] == 'H')
                return false;
    }

    frontier.push({start.fi, start.se, 0});
    vis[start.fi][start.se] = true;
    while(!frontier.empty()){
        minutes++;
        while(frontier.front()[2] < s * minutes && !frontier.empty()){
            array<int, 3> c = frontier.front();
            frontier.pop();
            if(t_forest[c[0]][c[1]] == 'H') continue;
            for(int j = 0; j < 4; j++){
                int new_x = c[0] + dx[j];
                int new_y = c[1] + dy[j];
                if(inside(new_x, new_y) && (t_forest[new_x][new_y] == 'G' || t_forest[new_x][new_y] == 'D') && !vis[new_x][new_y]){
                    if(t_forest[new_x][new_y] == 'D'){
                        return true;
                    }
                    frontier.push({new_x, new_y, c[2] + 1});
                    vis[new_x][new_y] = true;
                }
            }
        }

        int size = sz(bees);
        while(size--){
            array<int, 3> b = bees.front();
            bees.pop();
            for(int i = 0; i < 4; i++){
                int new_x = b[0] + dx[i];
                int new_y = b[1] + dy[i];
                if(inside(new_x, new_y) && (t_forest[new_x][new_y] == 'G' || t_forest[new_x][new_y] == 'M')){
                    bees.push({new_x, new_y, b[2] + 1});
                    t_forest[new_x][new_y] = 'H';
                }
            }
        }
    }
    return false;
}

int binary_search(){
    int le = 0, ri = n * n;
    while(le <= ri){
        int mid = le + ((ri - le) >> 1);
        if(check(mid)){
            le = mid + 1;
        }
        else{
            ri = mid - 1;
        }
    }
    return le - 1;
}

signed main(){
    ios_base::sync_with_stdio(false); cin.tie(0);
    cin >> n >> s;
    for(int i = 0; i < n; i++){
        cin >> forest[i];
        for(int j = 0; j < n; j++){
            if(forest[i][j] == 'H')
                hives.push({i, j, 0});
            else if(forest[i][j] == 'M')
                start = {i, j};
        }
    }
    cout << binary_search();
    return 0;
}

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 344 KB Output is correct
5 Correct 0 ms 344 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 249 ms 2452 KB Output is correct
8 Correct 1 ms 348 KB Output is correct
9 Correct 1 ms 600 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 1 ms 348 KB Output is correct
13 Correct 1 ms 348 KB Output is correct
14 Correct 1 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 1 ms 348 KB Output is correct
19 Correct 1 ms 344 KB Output is correct
20 Correct 1 ms 348 KB Output is correct
21 Correct 1 ms 348 KB Output is correct
22 Correct 1 ms 344 KB Output is correct
23 Correct 1 ms 348 KB Output is correct
24 Correct 1 ms 348 KB Output is correct
25 Correct 1 ms 348 KB Output is correct
26 Correct 1 ms 348 KB Output is correct
27 Correct 1 ms 348 KB Output is correct
28 Correct 1 ms 348 KB Output is correct
29 Correct 1 ms 348 KB Output is correct
30 Correct 1 ms 348 KB Output is correct
31 Correct 1 ms 348 KB Output is correct
32 Correct 1 ms 348 KB Output is correct
33 Correct 18 ms 860 KB Output is correct
34 Correct 16 ms 604 KB Output is correct
35 Correct 21 ms 820 KB Output is correct
36 Correct 26 ms 860 KB Output is correct
37 Correct 22 ms 860 KB Output is correct
38 Correct 26 ms 860 KB Output is correct
39 Correct 29 ms 860 KB Output is correct
40 Correct 27 ms 856 KB Output is correct
41 Correct 35 ms 860 KB Output is correct
42 Correct 38 ms 860 KB Output is correct
43 Correct 34 ms 860 KB Output is correct
44 Correct 45 ms 1092 KB Output is correct
45 Correct 48 ms 1116 KB Output is correct
46 Correct 41 ms 1116 KB Output is correct
47 Correct 53 ms 1188 KB Output is correct
48 Correct 54 ms 1116 KB Output is correct
49 Correct 56 ms 1332 KB Output is correct
50 Correct 62 ms 1336 KB Output is correct
51 Correct 66 ms 1444 KB Output is correct
52 Correct 60 ms 1368 KB Output is correct
53 Correct 74 ms 1368 KB Output is correct
54 Correct 78 ms 1368 KB Output is correct
55 Correct 69 ms 1596 KB Output is correct
56 Correct 90 ms 1628 KB Output is correct
57 Correct 89 ms 1756 KB Output is correct
58 Correct 79 ms 1624 KB Output is correct
59 Correct 120 ms 1628 KB Output is correct
60 Correct 106 ms 1920 KB Output is correct
61 Correct 91 ms 1916 KB Output is correct
62 Correct 122 ms 2136 KB Output is correct
63 Correct 185 ms 1936 KB Output is correct
64 Correct 236 ms 1884 KB Output is correct
65 Correct 206 ms 1932 KB Output is correct
66 Correct 203 ms 1936 KB Output is correct
67 Correct 199 ms 1936 KB Output is correct
68 Correct 179 ms 2136 KB Output is correct
69 Correct 160 ms 2020 KB Output is correct
70 Correct 154 ms 1880 KB Output is correct
71 Correct 179 ms 2012 KB Output is correct
72 Correct 194 ms 1884 KB Output is correct
73 Correct 21 ms 2752 KB Output is correct
74 Correct 233 ms 2896 KB Output is correct
75 Correct 262 ms 2820 KB Output is correct
76 Correct 246 ms 2816 KB Output is correct
77 Correct 238 ms 3080 KB Output is correct
78 Correct 238 ms 2652 KB Output is correct
79 Correct 220 ms 2648 KB Output is correct
80 Correct 244 ms 2904 KB Output is correct
81 Correct 231 ms 2712 KB Output is correct
82 Correct 236 ms 2652 KB Output is correct
83 Correct 247 ms 2540 KB Output is correct
84 Correct 251 ms 2552 KB Output is correct
85 Correct 234 ms 2744 KB Output is correct
86 Correct 236 ms 2584 KB Output is correct
87 Correct 236 ms 2572 KB Output is correct
88 Correct 256 ms 2424 KB Output is correct
89 Correct 229 ms 2444 KB Output is correct
90 Correct 239 ms 2640 KB Output is correct
91 Correct 231 ms 2392 KB Output is correct
92 Correct 247 ms 2420 KB Output is correct