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.
#include<cstdio>
#include<iostream>
#include<algorithm>
using namespace std;
char a[100][100];
int m=0,n=0;
int ad(int x,int y)
{
a[x][y]='.';
for(int i=-1; i<2; i++)
for(int j=-1; j<2; j++)
if(a[x+i][y+j]=='W'&&x+i>=0&&x+i<n&&y+j>=0&&y+j<m)
ad(x+i,y+j);
}
int main()
{
int ans=0;
scanf("%d%d",&n,&m);
getchar();
for(int i=0; i<n; i++)
{
for(int j=0; j<m; j++)
scanf("%c",&a[i][j]);
getchar();
}
for(int i=0; i<n; i++)
for(int j=0; j<m; j++)
if(a[i][j]=='W')
{
ad(i,j);
ans++;
}
printf("%d\n",ans);
return 0;
}Sample Output
3