Lake Counting
| Time Limit: 1000MS | Memory Limit: 65536K | |
| Total Submissions: 17917 | Accepted: 9069 |
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
3
#include <iostream>
using namespace std;
int n,m;
char map[101][101];
void dfs(int x,int y)
{
map[x][y]='.';
for(int dx=-1;dx<=1;dx++)
{
for(int dy=-1;dy<=1;dy++)
{
int nx=dx+x,ny=dy+y;
if(nx>=1&&nx<=n&&ny>=1&&ny<=m)
{
if(map[nx][ny]=='W')
{
dfs(nx,ny);
}
}
}
}
}
int solve()
{
int x=0;
for(int i=1;i<=n;i++)
{
for(int j=1;j<=m;j++)
{
if(map[i][j]=='W')
{
dfs(i,j);
x++;
}
}
}
return x;
}
int main()
{
cin>>n>>m;
for(int i=1;i<=n;i++)
{
for(int j=1;j<=m;j++)
{
cin>>map[i][j];
}
}
cout<<solve()<<endl;
return 0;
}