题解 | #单组_二维字符数组#

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 main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        int n = in.nextInt();
        int m = in.nextInt();
        in.nextLine();
        char[][] ch = new char[n][m];
	  	//读取字符数组
        for (int i = 0; i < n; i++) {
            String s = in.nextLine();
            for (int j = 0; j < m; j++) {
                ch[i][j] = s.charAt(j);
            }
        }
	  	//交换列
        int i = 0,j = m - 1;
        while(i<j){
            for(int k=0;k<n;k++){
                char temp = ch[k][i];
                ch[k][i] = ch[k][j];
                ch[k][j] = temp;
            }
            i++;
            j--;
        }
	  	//交换行
        i = 0;
        j = n - 1;
        while(i<j){
            for(int k=0;k<m;k++){
                char temp = ch[i][k];
                ch[i][k] = ch[j][k];
                ch[j][k] = temp;
                
            }
            i++;
            j--;
        }
	  	//输出
        for(i = 0;i<n;i++){
            for(j=0;j<m;j++)
                System.out.print(ch[i][j]);
            System.out.println();
        }
        


    }
}