大小写转换

<pre name="code" class="objc">#include<stdio.h>
int main()
{
	int ch;
	while( (ch=getchar()) != EOF)
	{
		if( ch>='a'&&ch<='z')
		{
			putchar(ch);
		}
		if( ch>='A'&&ch<='Z')
		{
			ch+=32;
			putchar(ch);
		}
	}
	return 0;
}