输出数目字菱形

输出数字菱形

public class TextPrintPictureDemo {public static void printNumberLozenge(int row){int i , j ; for(i = 1 ; i <= row ; i ++){for(j = 1 ; j <= row - i ; j ++){System.out.print(" ");}for(j = 1 ; j <= 2 * i - 1 ; j ++){if(j <= i){System.out.print(j);}else{System.out.print(2 * i - j);}}System.out.println();} for(i = 1 ; i <= row ; i ++){      for( j = 1 ; j <= i ; j ++)      System.out.print(" ");      for( j = 1 ; j <= 2 * (row - i) - 1 ; j ++)      if(j <= row - i ){System.out.print(j);}else{System.out.print(2 * (row - i) - j);}      System.out.println();      }}public static void main(String []args){System.out.println("输出数字菱形");printNumberLozenge(5);}}

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输出结果：

??????? 1
???? ?121
??? 12321

? 1234321
123454321
? 1234321
?? ?12321
???? ?121
?????? ?1
????

运用for双重循环：外循环可以控制行数，内循环在行的基础上控制每列的数目。

注意观察数据特征，提炼表达式。