#include <stdio.h>  
  
int main()  
{  
    char ch;  
    printf("请输入一个字符：");  
    scanf("%c",&ch);  
    if(ch >= 'A' && ch <= 'Z')  
        ch = ch + 32;  
    printf("转换成小写字母是：%c\n",ch);  
  
    return 0;  
}