java50题----19打印菱形

/*打印以下的菱形：   *  *** ************ *****  ***   *       */class Demo{private Demo(){}private static Demo instance = new Demo();public static Demo getInstance(){return instance;}public void print(int n){if(n%2 == 0)return;int mid = (n+1)/2;for(int i = 1; i <= n; i++){if(i < mid){for(int j = 1 ; j <= n; j++){if(j>=mid-(i-1) && j<=mid+i-1)System.out.print("*");elseSystem.out.print(" ");}System.out.println("");}else{for(int j = 1 ; j <= n; j++){if(j>=mid-(n-i) && j<=mid+n-i)System.out.print("*");elseSystem.out.print(" ");}System.out.println("");}}}}class MainClass {public static void main(String[] args) throws Exception{Demo d = Demo.getInstance();d.print(9);}}/**/