用java 空心菱形來改的

選我正解

public class MyClass {
    public static void main(String args[]) {
        int hangshu = 7; 
        int yiban = hangshu / 2 + 1; 
        int yibanduo = hangshu / 2; 
        for(int k = 1;k <= yiban;k++){ 
            for(int i = 1;i <= (yiban - k);i++){ 
                System.out.print(" "); 
            }
            if(k==1){
                System.out.print("*");
            } else {
                System.out.print("**"); 
            }
            for(int i = 1;i <= ( (k - 2) * 2 - 1);i++){
                System.out.print(" "); 
            } 
            if(k==2) {
                System.out.print("*"); 
            } else if(k != 1){
                System.out.print("**"); 
            } 
            System.out.println(); 
        } 
        
        for(int k = yibanduo;k >=1;k--){ 
            for(int i = 1;i <= (yiban - k);i++){ 
                System.out.print(" "); 
            } 
            if(k==1){
                System.out.print("*");
            } else {
                System.out.print("**"); 
            }
            for(int i = 1;i <= ( (k - 2) * 2- 1);i++){ 
                System.out.print(" "); 
            } 
            if(k==2) {
                System.out.print("*"); 
            } else if(k != 1){
                System.out.print("**"); 
            } 
            System.out.println(); 
        }
    }
}