Luo Gu P1141 01 mazes (dfs)

https://www.luogu.org/problem/P1141

Ideas: to find every communication block, marks of different communication different blocks, the number of tokens assigned to the communication to block

 1 // luogu-judger-enable-o2
 2 #include <cstdio>
 3 #include <iostream>
 4 #include <algorithm>
 5 #include <cmath>
 6 #include <queue>
 7 #include <vector>
 8 #include <cstring>
 9 #include <map>
10 #define mem(a) memset(a,0,sizeof(a))
11 using namespace std;
12 typedef long long ll;
13 const int maxn = 200005;
14 const ll INF = 0x3f3f3f3f3f ;
15  int dir [ 8 ] [ 2 ] = { 2 , 1 , 1 , 2 , - 2 , 1 , - 1 , 2 , 2 , - 1 , 1 , - 2 , - 2 , - 1 , - 1 , - 2 };
16  int dir2 [ 4 ] [ 2 ] = { 0 , 1 , 0 , - 1 , 1 ,0,-1,0};
17 bool flag;
18 int vis[1005][1005],sum[1000005];
19 int n,m,countt,num;
20 string s[1005];
21 void dfs(int x,int y){
22     countt++;
23     vis[x][y] = num;
24     for(int i = 0; i < 4; i++){
25                               }
32 int main()
33 {
34 
35     while(cin >> n >> m){
36         mem(vis);
37         mem(sum);
38         num = 1;
39         for(int i = 0; i < n; i++)
40             cin >> s[i];
41         for(int i = 0; i < n; i++){
42             for(int j = 0; j < n; j++){
43                 if(vis[i][j] == 0)
44                 {
45                     countt = 0;
46                     vis[i][j] = num;
47                     dfs(i,j);
48                     sum[num] = countt;
49                     //cout << sum[num] << endl;
50                     num++;
51                 }
52             }
53         }
54         int x, y;
55         //for(int i = 1; i < num; i++) cout << sum[i] << endl;
56         for(int i = 0; i < m; i++){
57             cin >> x >> y;
58             cout << sum[vis[x-1][y-1]] << endl;
59         }
60     }
61     return 0;
62 }