Lake Counting (P2386)

是简单的搜索题，可以深搜，也可以广搜。这里用的是深搜

记得要标记状态就行了。

#include<iostream>#include<cstdio>#include<cstring>#include<algorithm>using namespace std;#define N 105int n,m;char map[N][N];bool vist[N][N];int a[8][2]={{1,0},{1,1},{0,1},{-1,1},{-1,0},{-1,-1},{0,-1},{1,-1}};bool in(int i,int j){if (i>=0&&i<n&&j>=0&&j<m)return true;return false;}void bfs(int i,int j){vist[i][j]=true;int k;for (k=0;k<9;k++){int x=i+a[k][0];int y=j+a[k][1];if (in(x,y)&&map[x][y]=='W'&&!vist[x][y])bfs(x,y);}}int  main(){freopen("in.txt","r",stdin);int i,j,k;cin>>n>>m;for (i=0;i<n;i++){cin>>map[i];}int ans=0;memset(vist,false,sizeof(vist));for (i=0;i<n;i++){for (j=0;j<m;j++)  if (map[i][j]=='W'&&!vist[i][j]){bfs(i,j);ans++;}}cout<<ans<<endl;}

Lake Counting

Time Limit: 1000MS Memory Limit: 65536KTotal Submissions: 14593 Accepted: 7391

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

Sample Output

3

Hint

OUTPUT DETAILS:

There are three ponds: one in the upper left, one in the lower left,and one along the right side.

Source