程序功能介绍

```c
#include <stdio.h>
int main()
{char c,ll;printf("please enter a capital letter:");c=getchar();getchar();if (c>='A'&& c<='Z')	{ll=c+32;printf("Lowercase letter output:%c\n",ll);printf("ASCII value:%d\n",c);}else{       printf("Invalid input!\n");}return 0;
}