hdu1241 dfs

Posted 2020-08-06 %%%%%

链接改天再补 杭电又崩了。。。

题意：求“@”组成了多少个联通区域，每个点的8个方向都认为是相连的

思路：对每一个点进行搜索 当Map == @ && vis == 0 时 可进入搜索 每次进入搜索时 ans++ 搜索时将该联通区域所有的点标记 8个方向搜

AC代码：

 1 #include "iostream"
 2 #include "string.h"
 3 #include "stack"
 4 #include "queue"
 5 #include "map"
 6 #include "algorithm"
 7 #include "stdio.h"
 8 #include "math.h"
 9 #define ll long long
10 #define mem(a) memset(a,0,sizeof(a))
11 #define max(a,b) a > b ? a : b
12 #define min(a,b) a < b ? a : b
13 
14 using namespace std;
15 
16 int d[8][2] = {{0,1},{1,0},{0,-1},{-1,0},{-1,1},{1,1},{1,-1},{-1,-1}};
17 bool vis[1005][1005];
18 bool Map[1005][1005];
19 
20 struct Node
21 {
22     int xx,yy;
23 };
24 
25 void Dfs(int x,int y)
26 {
27     stack<Node>S;
28     Node now,next;
29     now.xx = x;
30     now.yy = y;
31     vis[x][y] = 1;
32     S.push(now);
33 
34     while(!S.empty())
35     {
36         now = S.top();
37         S.pop();
38 
39         for(int i=0; i<8; i++)
40         {
41             next.xx = now.xx + d[i][0];
42             next.yy = now.yy + d[i][1];
43 
44             if(Map[next.xx][next.yy] && !vis[next.xx][next.yy])
45             {
46                 vis[next.xx][next.yy] = 1;
47                 S.push(next);
48             }
49         }
50     }
51 }
52 
53 int main()
54 {
55     int n,m,i,j,ans;
56     char c;
57     while(scanf("%d%d",&m,&n)&&(m||n))
58     {
59         mem(vis);
60         mem(Map);
61         ans = 0;
62         for(i=1; i<=m; i++)
63             for(j=1; j<=n; j++)
64             {
65                 cin>>c;
66                 if(c==‘@‘)
67                     Map[i][j] = 1;
68                 if(c==‘*‘)
69                     Map[i][j] = 0;
70             }
71         for(i=1; i<=m; i++)
72             for(j=1; j<=n; j++)
73             {
74                 if(Map[i][j] && !vis[i][j])
75                 {
76                     ans++;
77                     Dfs(i,j);
78                 }
79             }
80         printf("%d\n",ans);
81     }
82     return 0;
83 }