Submission #835394

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
835394	2023-08-23T14:04:31 Z	mohammad_kilani	Mecho (IOI09_mecho)	C++17	93 / 100	141 ms	6308 KB

mecho

#include <bits/stdc++.h>
using namespace std;
#define mod 1000000007
#define oo 1000000010

const int N = 810;

int n , s;

char grid[N][N];

int cost[N][N];

int dr[] = {0 , 1,  0 , -1};
int dc[] = {1 , 0 , -1 , 0};

int sr , sc , er , ec;

int cost2[N][N];

void BFSH(){
	queue < pair< int , int > > q;
	memset(cost , -1, sizeof(cost));
	for(int i = 0;i < n;i++){
		for(int j = 0 ;j < n;j++){
			if(grid[i][j] == 'H'){
				q.push(make_pair(i , j));
				cost[i][j] = 0;
			}
		}
	}
	int row , col;
	while(!q.empty()){
		row = q.front().first;
		col = q.front().second;
		q.pop();
		for(int nr , nc , i = 0 ;i < 4;i++){
			nr = row + dr[i];
			nc = col + dc[i];
			if(nr < 0 || nr >= n || nc < 0 || nc >= n || grid[nr][nc] == 'T' ||  cost[nr][nc] != -1) continue;
			cost[nr][nc] = cost[row][col] + 1;
			q.push(make_pair(nr , nc));
		}
	}
}

bool check(int mid){
	for(int i = 0 ;i < n;i++) for(int j = 0 ;j < n;j++) cost2[i][j] = -1;
	cost2[sr][sc] = mid * s;
	queue < pair< int , int > > q;
	q.push(make_pair(sr, sc));
	int row , col;
	while(!q.empty()){
		row = q.front().first;
		col = q.front().second;
		q.pop();
		if(cost2[row][col] >= cost[row][col] * s) continue;
		for(int nr , nc , i = 0 ;i < 4;i++){
			nr = row + dr[i];
			nc = col + dc[i];
			if(nr < 0 || nr >= n || nc < 0 || nc >= n || grid[nr][nc] == 'T' || cost2[nr][nc] != -1) continue;
			cost2[nr][nc] = cost2[row][col] + 1;
			q.push(make_pair(nr , nc));
		}
	}
	//cout << "check " << mid << " " << cost2[er][ec] << " " << cost[er][ec] << endl;
	if(cost2[er][ec] == -1 || cost2[er][ec] == cost[er][ec] * s)
		return false;
	return true;
}

int main(){
	scanf("%d%d",&n,&s);
	for(int i = 0 ;i < n;i++){
		scanf("%s",grid[i]);
		for(int j = 0 ;j < n;j++){
			if(grid[i][j] == 'M')
				sr = i , sc = j;
			if(grid[i][j] == 'D')
				er = i , ec = j;
		}
	}
	BFSH();

	int low = 0 , high = cost[sr][sc] - 1 , mid , ans = -1;
	while(high >= low){
		mid = (low + high) / 2;
		if(check(mid))
			ans = mid , low = mid + 1;
		else
			high = mid - 1;
	}
	cout << ans << endl;
	return 0;
} 

Compilation message

mecho.cpp: In function 'int main()':
mecho.cpp:73:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   73 |  scanf("%d%d",&n,&s);
      |  ~~~~~^~~~~~~~~~~~~~
mecho.cpp:75:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |   scanf("%s",grid[i]);
      |   ~~~~~^~~~~~~~~~~~~~

Subtask #1

93.0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	2772 KB	Output is correct
2	Correct	1 ms	2772 KB	Output is correct
3	Correct	1 ms	2772 KB	Output is correct
4	Incorrect	3 ms	2772 KB	Output isn't correct
5	Correct	1 ms	2900 KB	Output is correct
6	Correct	1 ms	2948 KB	Output is correct
7	Correct	65 ms	6136 KB	Output is correct
8	Correct	1 ms	2900 KB	Output is correct
9	Correct	1 ms	2900 KB	Output is correct
10	Correct	1 ms	2900 KB	Output is correct
11	Correct	1 ms	2900 KB	Output is correct
12	Incorrect	1 ms	3028 KB	Output isn't correct
13	Correct	1 ms	3028 KB	Output is correct
14	Correct	1 ms	3028 KB	Output is correct
15	Correct	1 ms	2900 KB	Output is correct
16	Correct	2 ms	2900 KB	Output is correct
17	Correct	2 ms	2900 KB	Output is correct
18	Correct	1 ms	2900 KB	Output is correct
19	Correct	2 ms	2900 KB	Output is correct
20	Correct	1 ms	2900 KB	Output is correct
21	Correct	1 ms	3028 KB	Output is correct
22	Correct	1 ms	3028 KB	Output is correct
23	Correct	1 ms	3028 KB	Output is correct
24	Correct	2 ms	3028 KB	Output is correct
25	Correct	1 ms	3028 KB	Output is correct
26	Correct	2 ms	3028 KB	Output is correct
27	Correct	1 ms	3028 KB	Output is correct
28	Correct	1 ms	3028 KB	Output is correct
29	Correct	2 ms	3156 KB	Output is correct
30	Correct	1 ms	3028 KB	Output is correct
31	Correct	1 ms	3156 KB	Output is correct
32	Correct	2 ms	3156 KB	Output is correct
33	Correct	4 ms	4180 KB	Output is correct
34	Correct	4 ms	4180 KB	Output is correct
35	Correct	14 ms	4180 KB	Output is correct
36	Correct	4 ms	4436 KB	Output is correct
37	Correct	5 ms	4436 KB	Output is correct
38	Correct	19 ms	4436 KB	Output is correct
39	Correct	5 ms	4564 KB	Output is correct
40	Correct	6 ms	4564 KB	Output is correct
41	Correct	22 ms	4564 KB	Output is correct
42	Correct	6 ms	4820 KB	Output is correct
43	Correct	7 ms	4820 KB	Output is correct
44	Correct	34 ms	4820 KB	Output is correct
45	Correct	7 ms	4948 KB	Output is correct
46	Correct	8 ms	4948 KB	Output is correct
47	Correct	39 ms	4948 KB	Output is correct
48	Correct	8 ms	5204 KB	Output is correct
49	Correct	9 ms	5204 KB	Output is correct
50	Correct	39 ms	5204 KB	Output is correct
51	Correct	9 ms	5332 KB	Output is correct
52	Correct	10 ms	5332 KB	Output is correct
53	Correct	47 ms	5432 KB	Output is correct
54	Correct	10 ms	5588 KB	Output is correct
55	Correct	15 ms	5588 KB	Output is correct
56	Correct	55 ms	5632 KB	Output is correct
57	Correct	12 ms	5844 KB	Output is correct
58	Correct	14 ms	5844 KB	Output is correct
59	Correct	62 ms	5844 KB	Output is correct
60	Correct	13 ms	5972 KB	Output is correct
61	Correct	15 ms	6040 KB	Output is correct
62	Correct	77 ms	6032 KB	Output is correct
63	Correct	82 ms	6024 KB	Output is correct
64	Correct	141 ms	6028 KB	Output is correct
65	Correct	129 ms	5976 KB	Output is correct
66	Correct	91 ms	6028 KB	Output is correct
67	Correct	87 ms	5972 KB	Output is correct
68	Correct	38 ms	5968 KB	Output is correct
69	Correct	30 ms	6056 KB	Output is correct
70	Correct	29 ms	5972 KB	Output is correct
71	Correct	22 ms	5972 KB	Output is correct
72	Correct	27 ms	5968 KB	Output is correct
73	Correct	30 ms	6220 KB	Output is correct
74	Correct	49 ms	6304 KB	Output is correct
75	Correct	45 ms	6220 KB	Output is correct
76	Correct	42 ms	6308 KB	Output is correct
77	Correct	54 ms	6216 KB	Output is correct
78	Correct	55 ms	6276 KB	Output is correct
79	Correct	43 ms	6288 KB	Output is correct
80	Correct	43 ms	6280 KB	Output is correct
81	Correct	54 ms	6276 KB	Output is correct
82	Correct	43 ms	6288 KB	Output is correct
83	Correct	61 ms	6252 KB	Output is correct
84	Correct	51 ms	6240 KB	Output is correct
85	Correct	55 ms	6244 KB	Output is correct
86	Correct	55 ms	6164 KB	Output is correct
87	Correct	49 ms	6236 KB	Output is correct
88	Correct	60 ms	6188 KB	Output is correct
89	Correct	51 ms	6184 KB	Output is correct
90	Correct	63 ms	6188 KB	Output is correct
91	Correct	57 ms	6100 KB	Output is correct
92	Correct	61 ms	6192 KB	Output is correct