Lake Counting

谁践踏了优雅 2021-06-24 13:58 265阅读 0赞

Description

Due to recent rains, water has pooled in various places in Farmer John's field, which is represented by a rectangle of N x M (1 <= N <= 100; 1 <= M <= 100) squares. Each square contains either water ('W') or dry land ('.'). Farmer John would like to figure out how many ponds have formed in his field. A pond is a connected set of squares with water in them, where a square is considered adjacent to all eight of its neighbors.   
  
Given a diagram of Farmer John's field, determine how many ponds he has.

Input

\* Line 1: Two space-separated integers: N and M   
  
\* Lines 2..N+1: M characters per line representing one row of Farmer John's field. Each character is either 'W' or '.'. The characters do not have spaces between them.

Output

\* Line 1: The number of ponds in Farmer John's field.

Sample Input

10 12
    W........WW.
    .WWW.....WWW
    ....WW...WW.
    .........WW.
    .........W..
    ..W......W..
    .W.W.....WW.
    W.W.W.....W.
    .W.W......W.
    ..W.......W.

Sample Output

#include<stdio.h>
    int n,m;
    char a[101][101];
    void dfs(int x,int y)
    {
        if(x<0 || x>n || y<0 || y>m || a[x][y]!='W')
        return;
        else
        {
            a[x][y]='.';
            dfs(x-1,y);
            dfs(x-1,y+1);
            dfs(x-1,y-1);
            dfs(x,y-1);
            dfs(x,y+1);
            dfs(x+1,y+1);
            dfs(x+1,y-1);
            dfs(x+1,y);
        }
    }
    int main()
    {
        int i,j,count=0;
    
        //while(scanf("%d%d",&n,&m)!=EOF)
        //{
            scanf("%d%d",&n,&m);
            for(i=0;i<n;i++)
            scanf("%s",a[i]);
            for(i=0;i<n;i++)
            for(j=0;j<m;j++)
            if(a[i][j]=='W')
            {
                count++;
                dfs(i,j);
            }
    
          printf("%d\n",count);
       // }
        return 0;
    }