JAVA实现———菱形和空心菱形

1.菱形

    int sp = 12;
        for (int i = 0; i <= 10; i += 2) {
            for (int k = 1; k < sp; k++) {
                System.out.print(" ");
            }
            sp--;
            for (int j = 1; j < i; j++) {
                System.out.print("*");
            }
            System.out.println();
        }
        int as = 8;
        for (int i = 8; i > 0; i -= 2) {
            for (int k = 1; k < as; k++) {
                System.out.print(" ");
            }
            as++;
            for (int j = 1; j < i; j++) {
                System.out.print("*");
            }
            System.out.println();
        }

2.空心菱形

   int sp = 30;
        for (int i = 0; i < 21; i += 2) {
            for (int k = 1; k < sp; k++) {//1  ; <30 ; 29 29 2<29 3<28 0 10
                System.out.print(" ");
            }
            sp--;
            for (int j = 1; j < i; j++) {
                if (j == 1 || j == i - 1) {
                    System.out.print("*");
                } else {
                    System.out.print(" ");
                }
            }
            System.out.println();
        }

        int as = 20;
        for (int i = 18; i >= 1; i -= 2) {
            for (int k = 1; k < as; k++) {
                System.out.print(" ");
            }
            as++;
            for (int j = 0; j < i; j++) {
                if (j == 1 || j == i - 1) {
                    System.out.print("*");
                } else {
                    System.out.print(" ");
                }
            }
            System.out.println();
        }