C语言大写子母变小写

#include 

int main()
{
   char a,b,c;
	a=getchar();
	b=getchar();
	c=getchar();
	a=a+32;
	b=b+32;
	c=c+32;
	putchar(a);
	putchar(b);
	putchar(c);
	putchar('\n');
   return 0;
}