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답안 #258452

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
258452 2020-08-06T00:02:36 Z c4ts0up Mecho (IOI09_mecho) C++17
21 / 100
 654 ms 34424 KB 
/*
ID: c4ts0up
LANG: C++
TASK: Mecho
*/

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define pb push_back
#define ff first
#define ss second

const int NMAX = 805;
const int INF = 1e9;

int n, s;
pair <int,int> home, mecho;
char grid[NMAX][NMAX];
int dist[NMAX][NMAX];

// hace el check a una coordenada
bool Check(int row, int col) {
	return (0 <= row && row < n && 0 <= col && col < n);
}

// BFS para encontrar el tiempo requerido para que las abejas lleguen a un lugar
void EncontrarDistancias() {
	queue <pair <int,int> > to;
	set <pair <int,int> > seen;
	
	for (int i=0; i<n; i++) for (int j=0; j<n; j++) {
		if (grid[i][j] == 'H') to.push({i,j}), dist[i][j] = 0;
		else dist[i][j] = INF;
	}

	while (!to.empty()) {
		pair <int,int> curr = to.front();
		to.pop();
		
		// ya lo visitamos
		if (seen.count(curr)) continue;
		
		if (grid[curr.ff][curr.ss] == 'T' || grid[curr.ff][curr.ss] == 'D') {
			seen.insert(curr);
			continue;
		}
		
		// visitamos a todos los vecinos
		if (Check(curr.ff+1, curr.ss) && dist[curr.ff+1][curr.ss] > dist[curr.ff][curr.ss]+1) to.push({curr.ff+1, curr.ss}), dist[curr.ff+1][curr.ss] = dist[curr.ff][curr.ss]+1;
		if (Check(curr.ff-1, curr.ss) && dist[curr.ff-1][curr.ss] > dist[curr.ff][curr.ss]+1) to.push({curr.ff-1, curr.ss}), dist[curr.ff-1][curr.ss] = dist[curr.ff][curr.ss]+1;
		if (Check(curr.ff, curr.ss+1) && dist[curr.ff][curr.ss+1] > dist[curr.ff][curr.ss]+1) to.push({curr.ff, curr.ss+1}), dist[curr.ff][curr.ss+1] = dist[curr.ff][curr.ss]+1;
		if (Check(curr.ff, curr.ss-1) && dist[curr.ff][curr.ss-1] > dist[curr.ff][curr.ss]+1) to.push({curr.ff, curr.ss-1}), dist[curr.ff][curr.ss-1] = dist[curr.ff][curr.ss]+1;
		
		seen.insert(curr);
	}
}

bool BFS(int minutos) {
	bool seen[NMAX][NMAX];
	queue <pair <int, pair <int,int> > > to;
	to.push({0, mecho});
	
	for (int i=0; i<=n; i++) for (int j=0; j<=n; j++) seen[i][j] = false;
	
	while (!to.empty()) {
		pair <int, pair <int,int> > curr = to.front();
		to.pop();
		
		int r = curr.ss.ff;
		int c = curr.ss.ss;
		int pasos = curr.ff;
		
		// ya lo visitamos, no tenemos que volver
		if (seen[r][c]) continue;
		
		// no podemos atravesarlo
		if (grid[r][c] == 'T') {
			seen[r][c] = true;
			continue;
		}
		else if (grid[r][c] == 'D') return true;
		
		// ya está infestado de abejas, o sea, bloqueado
		if (minutos + (curr.ff/s) >= dist[r][c]) {
			seen[r][c] = true;
			continue;
		}
		
		// visitamos a todos los vecinos
		
		
		if (!seen[r+1][c] && Check(r+1, c)) to.push({pasos, {r+1,c}});
		if (!seen[r-1][c] && Check(r-1, c)) to.push({pasos, {r-1,c}});
		if (!seen[r][c+1] && Check(r, c+1)) to.push({pasos, {r,c+1}});
		if (!seen[r][c-1] && Check(r, c-1)) to.push({pasos, {r,c-1}});
		
		seen[r][c] = true;
	}
	
	return false;
}


int main() {
	/*//
	freopen("", "r", stdin);
	freopen("", "w", stdout);
	//*/
	
	cin >> n >> s;
	for (int i=0; i<n; i++) {
		string aux;
		cin >> aux;
		for (int j=0; j<n; j++) {
			grid[i][j] = aux[j];
			
			if (grid[i][j] == 'M') mecho = {i,j};
			else if (grid[i][j] == 'D') home = {i,j};
		}
		
		
	}
	
	EncontrarDistancias();
	
	if (!BFS(0)) {
		cout << -1 << endl;
		exit(0);
	}
	
	int lb = 0, ub = 1e6, mid;
	while (lb <= ub) {
		mid = (lb+ub)/2;
		
		if (BFS(mid)) lb = mid+1;
		else ub = mid-1;
	}
	
	//cerr << "lb = " << lb << "; ub = " << ub << "; mid = " << mid << endl;
	cout << ub-1 << endl;
	return 0;
}

Subtask #1
21.0 / 100.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 384 KB Output is correct
2 Incorrect 0 ms 384 KB Output isn't correct
3 Correct 0 ms 384 KB Output is correct
4 Incorrect 0 ms 384 KB Output isn't correct
5 Incorrect 0 ms 384 KB Output isn't correct
6 Incorrect 0 ms 384 KB Output isn't correct
7 Incorrect 483 ms 34168 KB Output isn't correct
8 Incorrect 1 ms 384 KB Output isn't correct
9 Incorrect 0 ms 384 KB Output isn't correct
10 Incorrect 1 ms 384 KB Output isn't correct
11 Incorrect 0 ms 384 KB Output isn't correct
12 Incorrect 2 ms 768 KB Output isn't correct
13 Incorrect 2 ms 640 KB Output isn't correct
14 Incorrect 3 ms 768 KB Output isn't correct
15 Correct 1 ms 384 KB Output is correct
16 Correct 1 ms 384 KB Output is correct
17 Correct 1 ms 512 KB Output is correct
18 Correct 1 ms 512 KB Output is correct
19 Correct 1 ms 512 KB Output is correct
20 Correct 1 ms 512 KB Output is correct
21 Correct 1 ms 640 KB Output is correct
22 Correct 1 ms 640 KB Output is correct
23 Correct 1 ms 640 KB Output is correct
24 Correct 2 ms 640 KB Output is correct
25 Correct 2 ms 768 KB Output is correct
26 Correct 2 ms 768 KB Output is correct
27 Correct 2 ms 768 KB Output is correct
28 Correct 2 ms 768 KB Output is correct
29 Correct 2 ms 896 KB Output is correct
30 Correct 2 ms 896 KB Output is correct
31 Correct 2 ms 896 KB Output is correct
32 Correct 3 ms 896 KB Output is correct
33 Correct 43 ms 7672 KB Output is correct
34 Correct 49 ms 7672 KB Output is correct
35 Incorrect 95 ms 7672 KB Output isn't correct
36 Correct 61 ms 9720 KB Output is correct
37 Correct 69 ms 9724 KB Output is correct
38 Incorrect 123 ms 9720 KB Output isn't correct
39 Correct 72 ms 11896 KB Output is correct
40 Correct 84 ms 11960 KB Output is correct
41 Incorrect 157 ms 11896 KB Output isn't correct
42 Correct 90 ms 14456 KB Output is correct
43 Correct 106 ms 14512 KB Output is correct
44 Incorrect 210 ms 14456 KB Output isn't correct
45 Correct 106 ms 17144 KB Output is correct
46 Correct 130 ms 17144 KB Output is correct
47 Incorrect 265 ms 17252 KB Output isn't correct
48 Correct 131 ms 20088 KB Output is correct
49 Correct 147 ms 20088 KB Output is correct
50 Incorrect 324 ms 20072 KB Output isn't correct
51 Correct 151 ms 23160 KB Output is correct
52 Correct 174 ms 23160 KB Output is correct
53 Incorrect 391 ms 23256 KB Output isn't correct
54 Correct 175 ms 26616 KB Output is correct
55 Correct 202 ms 26616 KB Output is correct
56 Incorrect 437 ms 26748 KB Output isn't correct
57 Correct 216 ms 30328 KB Output is correct
58 Correct 248 ms 30200 KB Output is correct
59 Incorrect 529 ms 30328 KB Output isn't correct
60 Correct 274 ms 34176 KB Output is correct
61 Correct 271 ms 34020 KB Output is correct
62 Incorrect 588 ms 34424 KB Output isn't correct
63 Incorrect 612 ms 33816 KB Output isn't correct
64 Correct 614 ms 33784 KB Output is correct
65 Incorrect 614 ms 33912 KB Output isn't correct
66 Incorrect 590 ms 33912 KB Output isn't correct
67 Incorrect 579 ms 33896 KB Output isn't correct
68 Incorrect 543 ms 33884 KB Output isn't correct
69 Incorrect 545 ms 33912 KB Output isn't correct
70 Incorrect 654 ms 33916 KB Output isn't correct
71 Incorrect 626 ms 33784 KB Output isn't correct
72 Incorrect 557 ms 33916 KB Output isn't correct
73 Incorrect 469 ms 34224 KB Output isn't correct
74 Correct 496 ms 34224 KB Output is correct
75 Incorrect 489 ms 34168 KB Output isn't correct
76 Incorrect 532 ms 34296 KB Output isn't correct
77 Incorrect 491 ms 34168 KB Output isn't correct
78 Incorrect 452 ms 34296 KB Output isn't correct
79 Correct 415 ms 34168 KB Output is correct
80 Incorrect 415 ms 34328 KB Output isn't correct
81 Incorrect 455 ms 34296 KB Output isn't correct
82 Incorrect 422 ms 34168 KB Output isn't correct
83 Incorrect 513 ms 34296 KB Output isn't correct
84 Correct 449 ms 34168 KB Output is correct
85 Incorrect 444 ms 34168 KB Output isn't correct
86 Incorrect 448 ms 34168 KB Output isn't correct
87 Incorrect 452 ms 34168 KB Output isn't correct
88 Incorrect 494 ms 34208 KB Output isn't correct
89 Correct 463 ms 34296 KB Output is correct
90 Incorrect 461 ms 34272 KB Output isn't correct
91 Incorrect 458 ms 34296 KB Output isn't correct
92 Incorrect 475 ms 34168 KB Output isn't correct