题解 | 数水坑

dfs

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void dfs(char[][] chs,int i,int j){
        if(chs[i][j]=='.'){
            return ;
        }
        chs[i][j]='.';
        if(i-1>=0){
            dfs(chs,i-1,j);
        }
        if(i+1<N){
            dfs(chs,i+1,j);
        }
        if(j-1>=0){
            dfs(chs,i,j-1);
        }
        if(j+1<M){
            dfs(chs,i,j+1);
        }
        if(i-1>=0&&j-1>=0){
            dfs(chs,i-1,j-1);
        }
        if(i-1>=0&&j+1<M){
            dfs(chs,i-1,j+1);
        }
        if(i+1<N&&j+1<M){
            dfs(chs,i+1,j+1);
        }
        if(i+1<N&&j-1>=0){
            dfs(chs,i+1,j-1);
        }
    }
    static int N;
    static int M;
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        N=in.nextInt();
        M=in.nextInt();
        char[][] chs=new char[N][M];
        for(int i=0;i<N;i++){
            chs[i]=in.next().toCharArray();
        }
        long count=0;
        for(int i=0;i<N;i++){
            for(int j=0;j<M;j++){
                if(chs[i][j]=='W'){
                    count++;
                    dfs(chs,i,j);
                }

            }
        }
        System.out.println(count);

    }
}