题解 | #牛牛的字符菱形#

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);
        char ch = in.next().charAt(0);
        int n = 5;
        int centerX = n / 2;
        int centerY = n / 2;

        for(int i = 0; i < n; ++i){
            for(int j = 0; j < n; ++j){
                if(Math.abs(i - centerX) + Math.abs(j - centerY) <= n / 2) System.out.print(ch);
                else System.out.print(" ");
            }
            System.out.println();
        }
        
    }
}

曼哈顿距离解法 借鉴了这个博主https://blog.csdn.net/Weraphael/article/details/128595858