hdoj problem 2952 Counting Sheep(深搜DFS)

Counting Sheep

http://acm.hdu.edu.cn/showproblem.php?pid=2952

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 2157    Accepted Submission(s): 1422

Problem Description

A while ago I had trouble sleeping. I used to lie awake, staring at the ceiling, for hours and hours. Then one day my grandmother suggested I tried counting sheep after I'd gone to bed. As always when my grandmother suggests things, I decided to try it out. The only problem was, there were no sheep around to be counted when I went to bed.


Creative as I am, that wasn't going to stop me. I sat down and wrote a computer program that made a grid of characters, where # represents a sheep, while . is grass (or whatever you like, just not sheep). To make the counting a little more interesting, I also decided I wanted to count flocks of sheep instead of single sheep. Two sheep are in the same flock if they share a common side (up, down, right or left). Also, if sheep A is in the same flock as sheep B, and sheep B is in the same flock as sheep C, then sheeps A and C are in the same flock.


Now, I've got a new problem. Though counting these sheep actually helps me fall asleep, I find that it is extremely boring. To solve this, I've decided I need another computer program that does the counting for me. Then I'll be able to just start both these programs before I go to bed, and I'll sleep tight until the morning without any disturbances. I need you to write this program for me.

 

Input

The first line of input contains a single number T, the number of test cases to follow.

Each test case begins with a line containing two numbers, H and W, the height and width of the sheep grid. Then follows H lines, each containing W characters (either # or .), describing that part of the grid.

 

Output

For each test case, output a line containing a single number, the amount of sheep flock son that grid according to the rules stated in the problem description.

Notes and Constraints
0 < T <= 100
0 < H,W <= 100

 

Sample Input

24 4#.#..#.##.##.#.#3 5###.#..#..#.###

 

Sample Output

63

 

Source

IDI Open 2009

 

Recommend

gaojie   |   We have carefully selected several similar problems for you:  1010 1258 1312 1426 1067 

/*

这是参考了人家的代码后AC的

Come On !

*/

#include<cstdio>
#include<cstring>
#include<cstdlib>
using namespace std;
char a[105][105];
int n,m,fx[4][4]={{1,0},{0,1},{-1,0},{0,-1}};//方向

void DFS(int x,int y)
{
     int i;
     for(i=0;i<4;i++)
     {
      int xx=fx[i][0]+x;
      int yy=fx[i][1]+y;
      if(xx>=0&&yy>=0&&xx<n&&yy<m&&a[xx][yy]=='#')//递归边界
      {
          a[xx][yy]='.';//标记已经遍历的
          DFS(xx,yy);
      }
    }
} 
int main()
{
  int T;
  scanf("%d",&T);
  while(T--)
  {
      int i,j,count;
      scanf("%d%d",&n,&m); 
      getchar();         
      for(i=0;i<n;i++)
          scanf("%s",a[i]);    
    
      
         count=0; 
          for(i=0;i<n;i++)
           for(j=0;j<m;j++)
                 if(a[i][j]=='#')
                 {
                     count++;
                     DFS(i,j);
            }
                       
           printf("%d\n",count); 
          
   } 
  return 0;    
}