#include "ctype.h"
int isalpha( int c )
{
return (unsigned int)( c | 32 ) - 'a' < 26;
}
int isdigit( int c )
{
return (unsigned int)c - '0' < 10;
}
int isalnum( int c )
{
return isalpha( c ) || isdigit( c );
}
int isspace( int c )
{
return c == ' ' || c == '\t' || c == '\r' || c == '\n';
}