답안 #624591

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
624591	2022-08-08T13:59:50 Z	jackkkk	Mecho (IOI09_mecho)	C++11	100 / 100	412 ms	2836 KB

mecho

// 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

#	결과	실행 시간	메모리	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