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Submission #103682

# Submission time Handle Problem Language Result Execution time Memory
103682 2019-04-02T04:21:10 Z tugushka Mecho (IOI09_mecho) C++14
57 / 100
 528 ms 66560 KB 
#include<bits/stdc++.h>
#define mp make_pair
#define pb push_back
using namespace std;

using pii = pair < short, short >;
const int N = 805;
const int dx[] = {1, -1, 0, 0}, dy[] = {0, 0, 1, -1};

char a[N][N];
pii mecho, home;
int n, s, hive[N][N];
bool used[N][N];

void hive_bfs(){
	memset( hive, 11, sizeof(hive) );
	queue < pii > q;
	for(int i = 0 ; i < n ; i++) for(int j = 0 ; j < n ; j++){
		if( a[i][j] == 'H' ){
			q.push( mp( i, j ) );
			hive[i][j] = 0;
		}
	}

	int dis = 0;
	while( !q.empty() ){
		dis += s;
		int sz = q.size();
		while( sz-- ){
			short int x, y;
			tie(x, y) = q.front();
			q.pop();
			for(int i = 0 ; i < 4 ; i++){
				short int tx = x+dx[i], ty = y+dy[i];
				if( tx < 0 || ty < 0 || tx >= n || ty >= n ) continue;
				if( a[tx][ty] == 'G' && hive[tx][ty] > 2e6 ){
					hive[tx][ty] = dis;
					q.push( mp( tx, ty ) );
				}
			}
		}
	}

	/*
	for(int i = 0 ; i < n ; i++){
		for(int j = 0 ; j < n ; j++){
			if( hive[i][j] > 2e6 ) printf("@@ ");
			else printf("%2d ", hive[i][j]);
		}
		printf("\n");
	}
	*/
}

bool mecho_bfs(int start_time){
	memset( used, 0, sizeof(used) );

	queue < pii > q;
	q.push( mecho );

	int dis = start_time;
	while( !q.empty() ){
		dis++;
		// cout << "dis " << dis << " : ";

		int sz = q.size();
		while( sz-- ){
			short int x, y;
			tie(x, y) = q.front();
			q.pop();
			for(int i = 0 ; i < 4 ; i++){
				short int tx = x+dx[i], ty = y+dy[i];
				if( tx < 0 || ty < 0 || tx >= n || ty >= n ) continue;
				if( !used[tx][ty] && a[tx][ty] == 'G' && hive[tx][ty] > dis ){
					used[tx][ty] = 1;
					if( used[ home.first ][ home.second ] ){
						return true;
					}
					// cout << "( " << tx << ',' << ty << " ), ";
					q.push( mp( tx, ty ) );
				}
			}
		}
		// cout << endl;
	}

	return used[ home.first ][ home.second ];
}

int main(){
	scanf("%d %d", &n, &s);
	for(int i = 0 ; i < n ; i++){
		scanf("%s", a[i]);
	}
	hive_bfs();
	for(int i = 0 ; i < n ; i++) for(int j = 0 ; j < n ; j++){
		if( a[i][j] == 'D' ){
			home = mp( i, j );
			a[i][j] = 'G';
		}
		if( a[i][j] == 'M' ){
			mecho = mp( i, j );
		}
	}

	if( !mecho_bfs( 0 ) ){
		printf("-1\n");
		return 0;
	}

	int l = 0, r = n*n, res;
	while( l <= r ){
		int mid = (l+r)/2;

		if( mecho_bfs( s*(mid) ) ){
			res = mid;
			l = mid+1;
		} else {
			r = mid-1;
		}
	}

	/*
	int res = 0;
	while( mecho_bfs( s*(res+1) ) ) res++;
	*/
	cout << res << endl;
}

Compilation message

mecho.cpp: In function 'int main()':
mecho.cpp:91:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &s);
  ~~~~~^~~~~~~~~~~~~~~~~
mecho.cpp:93:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%s", a[i]);
   ~~~~~^~~~~~~~~~~~
mecho.cpp:127:10: warning: 'res' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout << res << endl;
          ^~~

Subtask #1
57.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 3584 KB Output is correct
2 Correct 5 ms 3584 KB Output is correct
3 Correct 2 ms 3456 KB Output is correct
4 Correct 5 ms 3584 KB Output is correct
5 Correct 6 ms 3456 KB Output is correct
6 Correct 5 ms 3456 KB Output is correct
7 Correct 88 ms 4216 KB Output is correct
8 Correct 4 ms 3456 KB Output is correct
9 Correct 5 ms 3456 KB Output is correct
10 Correct 4 ms 3584 KB Output is correct
11 Correct 4 ms 3584 KB Output is correct
12 Incorrect 5 ms 3584 KB Output isn't correct
13 Incorrect 5 ms 3584 KB Output isn't correct
14 Correct 5 ms 3584 KB Output is correct
15 Correct 5 ms 3584 KB Output is correct
16 Correct 4 ms 3584 KB Output is correct
17 Correct 5 ms 3584 KB Output is correct
18 Correct 5 ms 3584 KB Output is correct
19 Correct 6 ms 3584 KB Output is correct
20 Correct 5 ms 3456 KB Output is correct
21 Correct 5 ms 3456 KB Output is correct
22 Correct 5 ms 3456 KB Output is correct
23 Correct 5 ms 3456 KB Output is correct
24 Correct 5 ms 3584 KB Output is correct
25 Correct 6 ms 3584 KB Output is correct
26 Correct 5 ms 3484 KB Output is correct
27 Correct 4 ms 3584 KB Output is correct
28 Correct 5 ms 3584 KB Output is correct
29 Correct 6 ms 3584 KB Output is correct
30 Correct 6 ms 3584 KB Output is correct
31 Correct 5 ms 3584 KB Output is correct
32 Correct 6 ms 3584 KB Output is correct
33 Correct 7 ms 3840 KB Output is correct
34 Runtime error 502 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
35 Correct 24 ms 3712 KB Output is correct
36 Correct 8 ms 3768 KB Output is correct
37 Runtime error 445 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
38 Correct 24 ms 3840 KB Output is correct
39 Correct 9 ms 3840 KB Output is correct
40 Runtime error 446 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
41 Correct 40 ms 3840 KB Output is correct
42 Correct 13 ms 3840 KB Output is correct
43 Runtime error 493 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
44 Correct 47 ms 3968 KB Output is correct
45 Correct 13 ms 3848 KB Output is correct
46 Runtime error 497 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
47 Correct 76 ms 3960 KB Output is correct
48 Correct 15 ms 3968 KB Output is correct
49 Runtime error 508 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
50 Correct 85 ms 4096 KB Output is correct
51 Correct 11 ms 3968 KB Output is correct
52 Runtime error 528 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
53 Correct 96 ms 4060 KB Output is correct
54 Correct 13 ms 4096 KB Output is correct
55 Runtime error 458 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
56 Correct 102 ms 3968 KB Output is correct
57 Correct 18 ms 4096 KB Output is correct
58 Runtime error 521 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
59 Correct 117 ms 4216 KB Output is correct
60 Correct 17 ms 4068 KB Output is correct
61 Runtime error 482 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
62 Correct 145 ms 4096 KB Output is correct
63 Correct 123 ms 4088 KB Output is correct
64 Runtime error 432 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
65 Correct 168 ms 4220 KB Output is correct
66 Correct 127 ms 4088 KB Output is correct
67 Correct 41 ms 4164 KB Output is correct
68 Correct 60 ms 4088 KB Output is correct
69 Correct 73 ms 4216 KB Output is correct
70 Correct 50 ms 4100 KB Output is correct
71 Correct 47 ms 4216 KB Output is correct
72 Incorrect 36 ms 4088 KB Output isn't correct
73 Incorrect 66 ms 4212 KB Output isn't correct
74 Correct 81 ms 4340 KB Output is correct
75 Correct 104 ms 4336 KB Output is correct
76 Correct 77 ms 4332 KB Output is correct
77 Correct 72 ms 4204 KB Output is correct
78 Correct 30 ms 4224 KB Output is correct
79 Correct 55 ms 4216 KB Output is correct
80 Correct 68 ms 4224 KB Output is correct
81 Correct 80 ms 4224 KB Output is correct
82 Correct 82 ms 4352 KB Output is correct
83 Correct 89 ms 4220 KB Output is correct
84 Correct 85 ms 4216 KB Output is correct
85 Correct 107 ms 4312 KB Output is correct
86 Correct 91 ms 4216 KB Output is correct
87 Correct 86 ms 4216 KB Output is correct
88 Correct 87 ms 4244 KB Output is correct
89 Correct 106 ms 4216 KB Output is correct
90 Correct 107 ms 4224 KB Output is correct
91 Correct 103 ms 4216 KB Output is correct
92 Correct 97 ms 4216 KB Output is correct