undefined reference to `isDigit'
Code:
eugene@eugene-laptop:~/cfiles$ cc 12.12.c
/tmp/cc7U4qkP.o: In function `convertToPostfix':
12.12.c:(.text+0xd6): undefined reference to `isDigit'
collect2: ld returned 1 exit status
Isn't isDigit part of the ctype header?
Code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
struct stackNode {
char data;
struct stackNode *nextPtr;
};
typedef struct stackNode StackNode;
typedef StackNode *StackNodePtr;
void convertToPostfix( char infix[], char postfix[] );
//isOperator completed
int isOperator( char c );
//precedence completed
int precedence( char operator1, char operator2 );
//push completed
void push( StackNodePtr *topPtr, char value );
//pop completed
char pop( StackNodePtr *topPtr );
char stackTop( StackNodePtr topPtr );
int isEmpty( StackNodePtr topPtr );
void printStack( StackNodePtr topPtr );
int main()
{
char iFix[ 10 ] = { 0 };
char pFix[ 10 ] = { 0 };
convertToPostfix( iFix, pFix );
return 0;
}
void convertToPostfix( char infix[], char postfix[] )
{
StackNode *stack = NULL;
char temp[ 2 ] = ")";
push( &stack, '(' );
/* APPENDS ")\0" to the end of infix */
strcat( infix, temp );
while( !isEmpty( stack ) ) {
if( isOperator( *infix ) ) {
}
if ( isDigit( *infix ) ) {
*postfix = *infix;
postfix += 2;
}
if ( *infix == '(' )
push( &stack, *infix );
if ( isOperator( *infix ) ) {
if ( precedence( stackTop( stack ), *infix ) == 0 || precedence( stackTop( stack ), *infix ) == 1 ) {
*postfix = pop( &stack );
postfix += 2;
push( &stack, *infix );
}
else
push( &stack, *infix );
}
if ( *infix == ')' ) {
while ( stackTop( stack ) != '(' ) {
*postfix = pop( &stack );
postfix += 2;
}
pop( &stack );
}
++infix;
}
}
void printStack( StackNode *topPtr )
{
while ( topPtr != NULL ) {
printf( "%c", topPtr->data );
topPtr = topPtr->nextPtr;
}
printf( "\n" );
}
int isEmpty( StackNode *topPtr )
{
if ( topPtr == NULL )
return 1;
else
return 0;
}
char pop( StackNode **topPtr )
{
char output;
StackNode *tempPtr = NULL;
output = ( *topPtr )->data;
tempPtr = *topPtr;
*topPtr = ( *topPtr )->nextPtr;
free( *topPtr );
return output;
}
char stackTop( StackNode *topPtr )
{
if ( topPtr != NULL )
return topPtr->data;
else
return ' ';
}
void push( StackNode **topPtr, char value )
{
StackNode *newPtr = NULL;
newPtr = malloc( sizeof( StackNode ) );
if ( newPtr != NULL ) {
newPtr->nextPtr = *topPtr;
newPtr->data = value;
*topPtr = newPtr;
}
}
int isOperator( char c )
{
if ( c == '+' || c == '-' || c == '*' || c == '/' || c == '^' || c == '%' )
return 1;
else
return 0;
}
//Determine if precedence of operator1 is greater(1), equal(0), or less then(-1) operator2
int precedence( char operator1, char operator2 )
{
int opValue[ 2 ] = { 0 };
char operator[ 2 ];
operator[ 0 ] = operator1;
operator[ 1 ] = operator2;
int i = 0;
for ( i = 0; i < 2; ++i ) {
switch( operator[ i ] ) {
case '+': case '-':
opValue[ i ] = 1;
break;
case '*': case '/': case '%':
opValue[ i ] = 2;
break;
case '^':
opValue[ i ] = 3;
break;
case '(': case ')':
opValue[ i ] = 4;
break;
}
}
if ( opValue[ 0 ] > opValue[ 1 ] )
return 1;
if ( opValue[ 0 ] == opValue[ 1 ] )
return 0;
else
return -1;
}
