java实现打印菱形

package cn.jbit.nestedloops;
import java.util.Scanner;
/**
 * 输入行数打印菱形
 */
public class Diamond {
  public static void main(String[] args) {
    int rows = 0; //菱形的行数
    Scanner input = new Scanner(System.in);
    System.out.print("请输入菱形行数：");
    rows = input.nextInt();
    while(rows%2 == 0){
      System.out.print("请输入奇数：");
      rows = input.nextInt();
    }
    int n = (rows+1)/2;
    //打印菱形的上半部分
    for(int i = 1; i <= n; i++){//外层循环变量i控制行数
      for(int j = 1; j <= n-i; j++){//内层循环变量j控制该行空格数
        System.out.print(" ");
      }
      for(int k = 1; k <= 2*i-1; k++){//内层循环变量k控制该行*号数
        System.out.print("*");
      }
      System.out.print("\n");
    }
    //打印菱形的下半部分
    for(int i = n-1; i >= 1; i--){
      for(int j = 1; j <= n-i; j++){
        System.out.print(" ");
      }
      for(int k = 1; k <= 2*i-1; k++){
        System.out.print("*");
      }
      System.out.print("\n");
    }
  }
}