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Submission #624591

# Submission time Handle Problem Language Result Execution time Memory
624591 2022-08-08T13:59:50 Z jackkkk Mecho (IOI09_mecho) C++11
100 / 100
 412 ms 2836 KB 
// Mecho
// https://oj.uz/problem/view/IOI09_mecho

#include <stdio.h>
#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <map>
#include <array>
#include <deque>
#include <unordered_map>
#include <unordered_set>
#include <set>
#include <algorithm>
#include <stdlib.h>
#include <math.h>
#include <list>
#include <float.h>
#include <climits>
#include <cmath>

using namespace std;

void quit() {
    cout.flush();
    exit(0);
}
int n, s;
pair<int, int> st, dest;
bool tree[800][800]; //contains trees and grass. bee hives are also trees
bool tmp[800][800];
bool mecho_done[800][800];
deque<pair<int, int>> hives, mecho, tmp1, tmp2, new_hives, new_mecho;
pair<int, int> gto[4] = {{0,1}, {0,-1}, {-1,0}, {1,0}};
bool in_grid(int a, int b){
    return a >= 0 && a < n && b >= 0 && b < n;
}
bool bee_can_go(int a, int b){
    return in_grid(a,b) && !(a == dest.first && b == dest.second) && !tree[a][b];
}
bool mecho_can_go(int a, int b){
    return in_grid(a,b) && !mecho_done[a][b] && !tree[a][b];
}
void bee_expand(){
    new_hives.clear();
    while(!hives.empty()){
        pair<int, int> curr = hives.front();
        int cx = curr.first, cy = curr.second;
        hives.pop_front();
        for(const auto &to : gto){
            int nx = to.first +cx, ny = to.second+cy;
            if(bee_can_go(nx, ny)){
                new_hives.emplace_back(nx, ny);
                tree[nx][ny]=1;
            }
        }
    }
    hives=new_hives;
}
bool finished;
bool mecho_expand(){
    //if can't expand anymore return false
    for(int i = 0; i < s; i++){
        new_mecho.clear();
        while(!mecho.empty()){
            pair<int, int> curr = mecho.front();
            int cx = curr.first, cy = curr.second;
            mecho.pop_front();
            if(tree[cx][cy]){
                continue;
            }
            for(const auto &to : gto){
                int nx = to.first +cx, ny = to.second+cy;
                if(mecho_can_go(nx, ny)){
                    new_mecho.emplace_back(nx, ny);
                    mecho_done[nx][ny]=1;
                }
                if(nx == dest.first && ny == dest.second){
                    //can get to dest
                    finished=true;
                    return false;
                }
            }
        }
        mecho=new_mecho;
    }
    return mecho.size()>0;
}

bool good(int wait_time){
    tmp1 = hives;
    tmp2 = mecho;
    for(int i = 0; i < 800; i++){
        for(int j = 0; j < 800; j++){
            mecho_done[i][j]=0;
            tmp[i][j]=tree[i][j];
        }
    }
    mecho_done[st.first][st.second]=1;
    finished=false;

    //propogate until can't
    for(int i = 0; i < wait_time; i++){
        bee_expand();
    }
    
    while(mecho_expand()){
        bee_expand();
        /*
        for(int i = 0; i < n; i++){
            for(int j = 0; j < n; j++){
                cerr <<tree[i][j] << " ";
            }
            cerr << "\n";
        }
        */
    }

    //reset variables
    for(int i = 0; i < 800; i++){
        for(int j = 0; j < 800; j++){
            tree[i][j]=tmp[i][j];
        }
    }
    hives=tmp1;
    mecho=tmp2;
    return finished;

}


int main(void){
    //freopen("qwer.in", "r", stdin);
    //freopen("qwer.out", "w", stdout);
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    cin >> n >> s;
    for(int i = 0; i < n; i++){
        string s; cin >> s;
        for(int j = 0; j < n; j++){
            if(s[j]=='T'){
                tree[i][j]=1;
            }
            else if(s[j]=='M'){
                st={i,j};
                mecho.emplace_back(i,j);
            }
            else if(s[j]=='D'){
                dest = {i,j};
            }
            else if(s[j] == 'H'){
                hives.emplace_back(i,j);
                tree[i][j]=1;
            }
        }
    }
    if(!good(0)){
        cout << "-1\n";
        quit();
    }
    int s = 0, e = 1e6;
    while(s != e){
        int md = (s+e+1)/2;
        if(good(md)){
            s=md;
        }
        else{
            e=md-1;
        }
    }
    cout << s << "\n";
    quit();
}

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 25 ms 2132 KB Output is correct
2 Correct 28 ms 2196 KB Output is correct
3 Correct 27 ms 2196 KB Output is correct
4 Correct 26 ms 2200 KB Output is correct
5 Correct 26 ms 2132 KB Output is correct
6 Correct 28 ms 2132 KB Output is correct
7 Correct 367 ms 2436 KB Output is correct
8 Correct 1 ms 2132 KB Output is correct
9 Correct 27 ms 2200 KB Output is correct
10 Correct 30 ms 2132 KB Output is correct
11 Correct 26 ms 2132 KB Output is correct
12 Correct 27 ms 2204 KB Output is correct
13 Correct 26 ms 2132 KB Output is correct
14 Correct 1 ms 2132 KB Output is correct
15 Correct 27 ms 2132 KB Output is correct
16 Correct 28 ms 2132 KB Output is correct
17 Correct 29 ms 2132 KB Output is correct
18 Correct 25 ms 2132 KB Output is correct
19 Correct 29 ms 2188 KB Output is correct
20 Correct 26 ms 2132 KB Output is correct
21 Correct 31 ms 2180 KB Output is correct
22 Correct 34 ms 2184 KB Output is correct
23 Correct 29 ms 2132 KB Output is correct
24 Correct 30 ms 2204 KB Output is correct
25 Correct 38 ms 2132 KB Output is correct
26 Correct 30 ms 2208 KB Output is correct
27 Correct 26 ms 2204 KB Output is correct
28 Correct 29 ms 2132 KB Output is correct
29 Correct 28 ms 2180 KB Output is correct
30 Correct 26 ms 2200 KB Output is correct
31 Correct 32 ms 2132 KB Output is correct
32 Correct 30 ms 2200 KB Output is correct
33 Correct 67 ms 2132 KB Output is correct
34 Correct 67 ms 2132 KB Output is correct
35 Correct 65 ms 2132 KB Output is correct
36 Correct 94 ms 2188 KB Output is correct
37 Correct 94 ms 2192 KB Output is correct
38 Correct 79 ms 2132 KB Output is correct
39 Correct 125 ms 2208 KB Output is correct
40 Correct 100 ms 2200 KB Output is correct
41 Correct 89 ms 2208 KB Output is correct
42 Correct 149 ms 2200 KB Output is correct
43 Correct 108 ms 2132 KB Output is correct
44 Correct 105 ms 2208 KB Output is correct
45 Correct 138 ms 2200 KB Output is correct
46 Correct 144 ms 2200 KB Output is correct
47 Correct 123 ms 2236 KB Output is correct
48 Correct 219 ms 2132 KB Output is correct
49 Correct 155 ms 2204 KB Output is correct
50 Correct 140 ms 2224 KB Output is correct
51 Correct 192 ms 2212 KB Output is correct
52 Correct 191 ms 2212 KB Output is correct
53 Correct 168 ms 2224 KB Output is correct
54 Correct 228 ms 2132 KB Output is correct
55 Correct 193 ms 2204 KB Output is correct
56 Correct 184 ms 2252 KB Output is correct
57 Correct 283 ms 2208 KB Output is correct
58 Correct 228 ms 2132 KB Output is correct
59 Correct 205 ms 2228 KB Output is correct
60 Correct 356 ms 2204 KB Output is correct
61 Correct 277 ms 2208 KB Output is correct
62 Correct 231 ms 2244 KB Output is correct
63 Correct 272 ms 2132 KB Output is correct
64 Correct 300 ms 2228 KB Output is correct
65 Correct 377 ms 2216 KB Output is correct
66 Correct 337 ms 2232 KB Output is correct
67 Correct 23 ms 2152 KB Output is correct
68 Correct 294 ms 2276 KB Output is correct
69 Correct 253 ms 2280 KB Output is correct
70 Correct 279 ms 2260 KB Output is correct
71 Correct 250 ms 2276 KB Output is correct
72 Correct 354 ms 2260 KB Output is correct
73 Correct 284 ms 2780 KB Output is correct
74 Correct 350 ms 2776 KB Output is correct
75 Correct 374 ms 2792 KB Output is correct
76 Correct 412 ms 2828 KB Output is correct
77 Correct 369 ms 2808 KB Output is correct
78 Correct 22 ms 2748 KB Output is correct
79 Correct 357 ms 2784 KB Output is correct
80 Correct 352 ms 2724 KB Output is correct
81 Correct 355 ms 2836 KB Output is correct
82 Correct 364 ms 2788 KB Output is correct
83 Correct 324 ms 2740 KB Output is correct
84 Correct 319 ms 2628 KB Output is correct
85 Correct 396 ms 2644 KB Output is correct
86 Correct 344 ms 2644 KB Output is correct
87 Correct 344 ms 2640 KB Output is correct
88 Correct 330 ms 2580 KB Output is correct
89 Correct 346 ms 2532 KB Output is correct
90 Correct 336 ms 2544 KB Output is correct
91 Correct 350 ms 2556 KB Output is correct
92 Correct 332 ms 2544 KB Output is correct