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Submission #258410

# Submission time Handle Problem Language Result Execution time Memory
258410 2020-08-05T22:45:59 Z c4ts0up Mecho (IOI09_mecho) C++17
21 / 100
 1000 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 (!seen.count({curr.ff+1, curr.ss}) && Check(curr.ff+1, curr.ss)) to.push({curr.ff+1, curr.ss}), dist[curr.ff+1][curr.ss] = min(dist[curr.ff+1][curr.ss], dist[curr.ff][curr.ss]+1);
		if (!seen.count({curr.ff-1, curr.ss}) && Check(curr.ff-1, curr.ss)) to.push({curr.ff-1, curr.ss}), dist[curr.ff-1][curr.ss] = min(dist[curr.ff-1][curr.ss], dist[curr.ff][curr.ss]+1);
		if (!seen.count({curr.ff, curr.ss+1}) && Check(curr.ff, curr.ss+1)) to.push({curr.ff, curr.ss+1}), dist[curr.ff][curr.ss+1] = min(dist[curr.ff][curr.ss+1], dist[curr.ff][curr.ss]+1);
		if (!seen.count({curr.ff, curr.ss-1}) && Check(curr.ff, curr.ss-1)) to.push({curr.ff, curr.ss-1}), dist[curr.ff][curr.ss-1] = min(dist[curr.ff][curr.ss-1], dist[curr.ff][curr.ss]+1);
		
		seen.insert(curr);
	}
}

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

# Verdict Execution time Memory Grader output
1 Correct 1 ms 512 KB Output is correct
2 Incorrect 0 ms 384 KB Output isn't correct
3 Correct 1 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 Execution timed out 1089 ms 34168 KB Time limit exceeded
8 Incorrect 1 ms 384 KB Output isn't correct
9 Incorrect 1 ms 384 KB Output isn't correct
10 Incorrect 1 ms 384 KB Output isn't correct
11 Incorrect 1 ms 384 KB Output isn't correct
12 Incorrect 2 ms 768 KB Output isn't correct
13 Incorrect 3 ms 692 KB Output isn't correct
14 Incorrect 6 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 384 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 512 KB Output is correct
22 Correct 2 ms 512 KB Output is correct
23 Correct 2 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 3 ms 768 KB Output is correct
27 Correct 2 ms 768 KB Output is correct
28 Correct 3 ms 768 KB Output is correct
29 Correct 3 ms 896 KB Output is correct
30 Correct 3 ms 768 KB Output is correct
31 Correct 3 ms 896 KB Output is correct
32 Correct 4 ms 896 KB Output is correct
33 Correct 62 ms 7544 KB Output is correct
34 Correct 87 ms 7672 KB Output is correct
35 Incorrect 793 ms 7672 KB Output isn't correct
36 Correct 95 ms 9592 KB Output is correct
37 Correct 97 ms 9592 KB Output is correct
38 Execution timed out 1094 ms 9776 KB Time limit exceeded
39 Correct 95 ms 11768 KB Output is correct
40 Correct 125 ms 11768 KB Output is correct
41 Execution timed out 1091 ms 12088 KB Time limit exceeded
42 Correct 127 ms 14328 KB Output is correct
43 Correct 154 ms 14200 KB Output is correct
44 Execution timed out 1098 ms 14456 KB Time limit exceeded
45 Correct 158 ms 17016 KB Output is correct
46 Correct 185 ms 17016 KB Output is correct
47 Execution timed out 1090 ms 17016 KB Time limit exceeded
48 Correct 204 ms 20052 KB Output is correct
49 Correct 215 ms 19960 KB Output is correct
50 Execution timed out 1085 ms 19960 KB Time limit exceeded
51 Correct 211 ms 23160 KB Output is correct
52 Correct 329 ms 23164 KB Output is correct
53 Execution timed out 1097 ms 23288 KB Time limit exceeded
54 Correct 256 ms 26744 KB Output is correct
55 Correct 306 ms 26744 KB Output is correct
56 Execution timed out 1082 ms 26884 KB Time limit exceeded
57 Correct 294 ms 30456 KB Output is correct
58 Correct 347 ms 30200 KB Output is correct
59 Execution timed out 1081 ms 30476 KB Time limit exceeded
60 Correct 390 ms 34296 KB Output is correct
61 Correct 395 ms 34168 KB Output is correct
62 Execution timed out 1097 ms 34172 KB Time limit exceeded
63 Execution timed out 1096 ms 33912 KB Time limit exceeded
64 Execution timed out 1097 ms 33912 KB Time limit exceeded
65 Execution timed out 1101 ms 33912 KB Time limit exceeded
66 Execution timed out 1091 ms 34040 KB Time limit exceeded
67 Execution timed out 1078 ms 33856 KB Time limit exceeded
68 Execution timed out 1094 ms 33912 KB Time limit exceeded
69 Execution timed out 1097 ms 33912 KB Time limit exceeded
70 Execution timed out 1095 ms 33872 KB Time limit exceeded
71 Execution timed out 1094 ms 33972 KB Time limit exceeded
72 Incorrect 763 ms 33912 KB Output isn't correct
73 Execution timed out 1090 ms 34340 KB Time limit exceeded
74 Execution timed out 1095 ms 34296 KB Time limit exceeded
75 Execution timed out 1086 ms 34296 KB Time limit exceeded
76 Execution timed out 1082 ms 34180 KB Time limit exceeded
77 Execution timed out 1099 ms 34296 KB Time limit exceeded
78 Execution timed out 1095 ms 34344 KB Time limit exceeded
79 Execution timed out 1095 ms 34228 KB Time limit exceeded
80 Execution timed out 1094 ms 34168 KB Time limit exceeded
81 Execution timed out 1098 ms 34168 KB Time limit exceeded
82 Execution timed out 1084 ms 34296 KB Time limit exceeded
83 Execution timed out 1093 ms 34168 KB Time limit exceeded
84 Execution timed out 1097 ms 34264 KB Time limit exceeded
85 Execution timed out 1097 ms 34316 KB Time limit exceeded
86 Execution timed out 1094 ms 34296 KB Time limit exceeded
87 Execution timed out 1095 ms 34360 KB Time limit exceeded
88 Execution timed out 1098 ms 34296 KB Time limit exceeded
89 Execution timed out 1096 ms 34424 KB Time limit exceeded
90 Execution timed out 1097 ms 34296 KB Time limit exceeded
91 Execution timed out 1096 ms 34168 KB Time limit exceeded
92 Execution timed out 1092 ms 34168 KB Time limit exceeded