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Submission #258432

# Submission time Handle Problem Language Result Execution time Memory
258432 2020-08-05T23:05:37 Z c4ts0up Mecho (IOI09_mecho) C++17
21 / 100
 1000 ms 35068 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) {
	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-1)/s) >= dist[curr.ss.ff][curr.ss.ss]) {
			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

# Verdict Execution time Memory Grader output
1 Correct 0 ms 288 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 838 ms 35064 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 1 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 4 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 3 ms 768 KB Output is correct
26 Correct 3 ms 768 KB Output is correct
27 Correct 3 ms 824 KB Output is correct
28 Correct 3 ms 896 KB Output is correct
29 Correct 2 ms 896 KB Output is correct
30 Correct 3 ms 896 KB Output is correct
31 Correct 3 ms 896 KB Output is correct
32 Correct 4 ms 896 KB Output is correct
33 Correct 58 ms 7800 KB Output is correct
34 Correct 68 ms 7800 KB Output is correct
35 Incorrect 130 ms 7928 KB Output isn't correct
36 Correct 87 ms 9932 KB Output is correct
37 Correct 89 ms 9848 KB Output is correct
38 Incorrect 170 ms 9848 KB Output isn't correct
39 Correct 94 ms 12152 KB Output is correct
40 Correct 116 ms 12216 KB Output is correct
41 Incorrect 218 ms 12152 KB Output isn't correct
42 Correct 121 ms 14712 KB Output is correct
43 Correct 142 ms 14712 KB Output is correct
44 Incorrect 287 ms 14840 KB Output isn't correct
45 Correct 149 ms 17400 KB Output is correct
46 Correct 173 ms 17400 KB Output is correct
47 Incorrect 353 ms 17404 KB Output isn't correct
48 Correct 183 ms 20344 KB Output is correct
49 Correct 209 ms 20344 KB Output is correct
50 Incorrect 703 ms 20388 KB Output isn't correct
51 Correct 217 ms 23580 KB Output is correct
52 Correct 258 ms 23696 KB Output is correct
53 Incorrect 514 ms 23672 KB Output isn't correct
54 Correct 254 ms 27192 KB Output is correct
55 Correct 453 ms 27096 KB Output is correct
56 Incorrect 586 ms 27128 KB Output isn't correct
57 Correct 284 ms 30840 KB Output is correct
58 Correct 486 ms 30828 KB Output is correct
59 Execution timed out 1095 ms 30840 KB Time limit exceeded
60 Correct 388 ms 34808 KB Output is correct
61 Correct 410 ms 34824 KB Output is correct
62 Incorrect 851 ms 34992 KB Output isn't correct
63 Incorrect 886 ms 34424 KB Output isn't correct
64 Correct 832 ms 34608 KB Output is correct
65 Incorrect 860 ms 34436 KB Output isn't correct
66 Incorrect 854 ms 34424 KB Output isn't correct
67 Incorrect 811 ms 34424 KB Output isn't correct
68 Incorrect 860 ms 34484 KB Output isn't correct
69 Incorrect 852 ms 34608 KB Output isn't correct
70 Incorrect 853 ms 34424 KB Output isn't correct
71 Incorrect 797 ms 34496 KB Output isn't correct
72 Incorrect 739 ms 34680 KB Output isn't correct
73 Incorrect 810 ms 34936 KB Output isn't correct
74 Correct 841 ms 35000 KB Output is correct
75 Incorrect 893 ms 34808 KB Output isn't correct
76 Incorrect 837 ms 34944 KB Output isn't correct
77 Incorrect 842 ms 34936 KB Output isn't correct
78 Incorrect 757 ms 34936 KB Output isn't correct
79 Correct 752 ms 34808 KB Output is correct
80 Incorrect 733 ms 34788 KB Output isn't correct
81 Incorrect 760 ms 34832 KB Output isn't correct
82 Incorrect 751 ms 34936 KB Output isn't correct
83 Incorrect 741 ms 34904 KB Output isn't correct
84 Correct 784 ms 35068 KB Output is correct
85 Incorrect 775 ms 34916 KB Output isn't correct
86 Incorrect 765 ms 34776 KB Output isn't correct
87 Incorrect 776 ms 34936 KB Output isn't correct
88 Incorrect 804 ms 34808 KB Output isn't correct
89 Correct 794 ms 35064 KB Output is correct
90 Incorrect 804 ms 34812 KB Output isn't correct
91 Incorrect 801 ms 34756 KB Output isn't correct
92 Incorrect 805 ms 35040 KB Output isn't correct