程序代码：

#include<stdio.h>
int main()
{
    printf("\
      *\n\
     ***\n\
    *****\n\
   *******\n\
  *********\n\

 ***********\n\
*************\n\
");
    return 0;
}

程序代码：

int main()
{
    int line;
    int n;
    int a,b,d;
    char letter,e;

    printf("===============================================================================\n");
    printf("***************************欢迎来到美丽的字母世界******************************\n");
    printf("===============================================================================\n");


/*对输入数据进行检测*/


    do{
       printf("请输入1到26之间您想输入的的数字: ");
       scanf("%d",&n);
      }while(n <= 0 || n >=27);

    /*判断并且打印字母菱形的上半部分*/

    for(line = 1 ;line <= n ;line++)
    {
        letter = 65;

        for(a = 1;a <= n-line;a++)
        {
            printf(" ");   /*空格*/
        }
        for(b = 1;b <= line;b++)  /*打印左半部分*/
        {
            printf("%c",letter);
            letter += 1;
            e = letter;
        }
        letter = e - 2;
        for(d = 2;d <=line;d++)   /*打印右半部分*/
        {
          printf("%c",letter);
          letter -= 1;

        }
        printf("\n");
    }

    /*打印字母菱形的下半部分*/

    for(line = 1 ;line <= n ;line++)
    {
        letter = 65;
        for(a = 1;a <= line;a++)
        {
            printf(" ");  /*空格*/
        }
        for(b = 1;b <=(n -line) ;b++)  /*打印左半部分*/
        {
            printf("%c",letter);
            letter += 1;
            e = letter;
        }
        letter = e-2;
        for(d = 2;d <= n-line;d++)   /*打印右半部分*/
        {
            printf("%c",letter);
            letter -= 1;
        }

        printf("\n");
    }
    return 0;
}