POJ 2386 lake counting

POJ 2386 lake counting

本题主要是运用dfs来计算lake的数目：
（Scanner没有nextChar()方法。第一次知道^_）

import java.util.Scanner;

public class poj2386 {

static char[][] lake=new char[100][100];
static int n=0,m=0;
static int count=0;

public static void main(String[] args) {
    Scanner s=new Scanner(System.in);
    n=s.nextInt();m=s.nextInt();
    String str;
    //input
    for (int i = 0; i < n; i++) {
        str=s.next();
        for (int j = 0; j < m; j++) {
            lake[i][j]=str.charAt(j);
        }
    }
    //遍历
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            if (lake[i][j]=='W'){
                dfs(i,j);
                count++;
            }
        }
    }
    System.out.println(count);
}
//不断dfs直到所有的附件可接触的点，均更换为'.'
public static void dfs(int x,int y){
    lake[x][y]='.';
    for (int i = -1; i <=1 ; i++) {
        for (int j = -1; j <= 1; j++) {
            int nx = x + i, ny = y + j;
            if (0 <= nx && nx < n && ny >= 0 && ny < m && lake[nx][ny] == 'W') {
                dfs(nx, ny);
            }
        }
    }
}

}