POJ2386 Lake Counting 图DFS

找出有多少个”水洼”(W的联通块)

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

解题思路

DFS

代码

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int maxn = 110;
char pic[maxn][maxn];
int vis[maxn][maxn];
int high,width;
int cnt = 0;
void dfs(int x,int y)
{
    //第x行，第y列
    if(pic[x][y] == ‘.‘ || vis[x][y]) return;
    if(x<0 || y<0 || x>=high || y>=width) return;
    vis[x][y] = 1;
    dfs(x-1,y);dfs(x+1,y);dfs(x,y+1);dfs(x,y-1);
    dfs(x-1,y-1);dfs(x-1,y+1);dfs(x+1,y-1);dfs(x+1,y+1);
}
int main()
{
    scanf("%d%d",&high,&width);
    for(int i = 0 ; i < high ; i ++) scanf("%s",pic[i]);
    for(int i = 0 ; i < high ; i ++) {
        for(int j = 0 ; j < width ; j ++) {
            if(pic[i][j] == ‘.‘) continue;
            if(vis[i][j] == 0) {
                dfs(i,j);
                cnt ++;
            }
        }
    }
    printf("%d\n",cnt);
    return 0;
}