题解 | #字母大小写转换#

int main()
{
    char ch = '0';
    while ((scanf ("%c",&ch)) != EOF)
    {
        if (ch >= 'A' && ch <= 'Z')
        {
            printf ("%c\n",ch+32);
        }
        else if (ch >= 'a' && ch <= 'z')
        {
            printf ("%c\n",ch-32);
        }
        else 
        {
            continue;
        }
    }
    return 0;
}