C语言:输入字符,输出前后两字符及其ASCALL值!

问题:请从键盘读入一个字符(该字符在a之后,z之前或者该字符在A之后在Z之前),要求输出该字符的前后两个字符,以及前后两个字符的ASCALL值!

代码1:

#include 
int main()
{
char ch1;
printf("please input char:");
scanf("%c",&ch1);
printf("ch1 = %c , ch1= %d \n",ch1,ch1);
printf("ch1 = %c , ch1= %d \n",ch1-1,ch1-1);
printf("ch1 = %c , ch1= %d \n",ch1+1,ch1+1);
 } 

运行结果:

please input char:h
ch1 = h , ch1= 104
ch1 = g , ch1= 103
ch1 = i , ch1= 105