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Submission #103675

# Submission time Handle Problem Language Result Execution time Memory
103675 2019-04-02T04:03:32 Z tugushka Mecho (IOI09_mecho) C++14
57 / 100
 315 ms 66560 KB 
#include<bits/stdc++.h>
#define mp make_pair
#define pb push_back
using namespace std;

using pii = pair < int, int >;
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-- ){
			int x, y;
			tie(x, y) = q.front();
			q.pop();
			for(int i = 0 ; i < 4 ; i++){
				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-- ){
			int x, y;
			tie(x, y) = q.front();
			q.pop();
			for(int i = 0 ; i < 4 ; i++){
				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;
					// 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:88:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &s);
  ~~~~~^~~~~~~~~~~~~~~~~
mecho.cpp:90:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%s", a[i]);
   ~~~~~^~~~~~~~~~~~
mecho.cpp:124:10: 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 4 ms 3456 KB Output is correct
2 Correct 4 ms 3456 KB Output is correct
3 Correct 4 ms 3456 KB Output is correct
4 Correct 4 ms 3584 KB Output is correct
5 Correct 4 ms 3456 KB Output is correct
6 Correct 5 ms 3456 KB Output is correct
7 Correct 92 ms 4220 KB Output is correct
8 Correct 5 ms 3456 KB Output is correct
9 Correct 5 ms 3456 KB Output is correct
10 Correct 6 ms 3456 KB Output is correct
11 Correct 4 ms 3456 KB Output is correct
12 Incorrect 4 ms 3584 KB Output isn't correct
13 Incorrect 5 ms 3584 KB Output isn't correct
14 Correct 4 ms 3584 KB Output is correct
15 Correct 6 ms 3584 KB Output is correct
16 Correct 5 ms 3584 KB Output is correct
17 Correct 6 ms 3456 KB Output is correct
18 Correct 6 ms 3504 KB Output is correct
19 Correct 5 ms 3584 KB Output is correct
20 Correct 3 ms 3584 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 3584 KB Output is correct
24 Correct 6 ms 3584 KB Output is correct
25 Correct 5 ms 3584 KB Output is correct
26 Correct 5 ms 3584 KB Output is correct
27 Correct 5 ms 3584 KB Output is correct
28 Correct 5 ms 3584 KB Output is correct
29 Correct 5 ms 3584 KB Output is correct
30 Correct 6 ms 3556 KB Output is correct
31 Correct 6 ms 3584 KB Output is correct
32 Correct 5 ms 3556 KB Output is correct
33 Correct 8 ms 3712 KB Output is correct
34 Runtime error 284 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
35 Correct 21 ms 3712 KB Output is correct
36 Correct 10 ms 3840 KB Output is correct
37 Runtime error 258 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
38 Correct 26 ms 3840 KB Output is correct
39 Correct 11 ms 3840 KB Output is correct
40 Runtime error 256 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
41 Correct 34 ms 3840 KB Output is correct
42 Correct 11 ms 3968 KB Output is correct
43 Runtime error 272 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
44 Correct 56 ms 4088 KB Output is correct
45 Correct 13 ms 3968 KB Output is correct
46 Runtime error 269 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
47 Correct 47 ms 3968 KB Output is correct
48 Correct 13 ms 3968 KB Output is correct
49 Runtime error 288 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
50 Correct 67 ms 3968 KB Output is correct
51 Correct 16 ms 3968 KB Output is correct
52 Runtime error 300 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
53 Correct 77 ms 3968 KB Output is correct
54 Correct 17 ms 4096 KB Output is correct
55 Runtime error 267 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
56 Correct 124 ms 4092 KB Output is correct
57 Correct 21 ms 4096 KB Output is correct
58 Runtime error 315 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
59 Correct 136 ms 4096 KB Output is correct
60 Correct 21 ms 4096 KB Output is correct
61 Runtime error 252 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
62 Correct 133 ms 4344 KB Output is correct
63 Correct 106 ms 4096 KB Output is correct
64 Runtime error 267 ms 66560 KB Execution killed with signal 9 (could be triggered by violating memory limits)
65 Correct 179 ms 4088 KB Output is correct
66 Correct 136 ms 4088 KB Output is correct
67 Correct 37 ms 4088 KB Output is correct
68 Correct 62 ms 4088 KB Output is correct
69 Correct 53 ms 4216 KB Output is correct
70 Correct 54 ms 4228 KB Output is correct
71 Correct 42 ms 4224 KB Output is correct
72 Incorrect 35 ms 4224 KB Output isn't correct
73 Incorrect 78 ms 4320 KB Output isn't correct
74 Correct 67 ms 4192 KB Output is correct
75 Correct 67 ms 4320 KB Output is correct
76 Correct 56 ms 4320 KB Output is correct
77 Correct 63 ms 4324 KB Output is correct
78 Correct 30 ms 4220 KB Output is correct
79 Correct 67 ms 4220 KB Output is correct
80 Correct 58 ms 4228 KB Output is correct
81 Correct 76 ms 4220 KB Output is correct
82 Correct 74 ms 4220 KB Output is correct
83 Correct 89 ms 4264 KB Output is correct
84 Correct 99 ms 4264 KB Output is correct
85 Correct 94 ms 4264 KB Output is correct
86 Correct 84 ms 4256 KB Output is correct
87 Correct 89 ms 4384 KB Output is correct
88 Correct 100 ms 4280 KB Output is correct
89 Correct 106 ms 4316 KB Output is correct
90 Correct 95 ms 4316 KB Output is correct
91 Correct 93 ms 4300 KB Output is correct
92 Correct 96 ms 4324 KB Output is correct