Problem with expression

[cool17]

#include "expression.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
 
 
xContainer splitTerm(string,int,int);
 
 
 
expContainer createExpression()
{
    expContainer exp;
 
    /*allocate memory*/
    exp = (expContainer)malloc(sizeof(struct expressions));
    if(exp != NULL)
    {
      /*set inital terms to zero*/
        exp->numberOfTerms = 0;
        return exp; /*return pointer*/
    }
    else
        printf("Out Of Heap!!!\n");
        return NULL;
 
}
 
void string2Expression(string inString,expContainer* inExp)
{
    string tempString;
    int length;
    int i=0, j=0,sign=0;
 
    tempString = (string)calloc(1,sizeof(char));
    /*get string length*/
    length = strlen(inString);
 
    /*determine first term sign*/
 
    if(inString[0] == '-')
        sign = 0;
 
    else if(inString[0] == '+')
        sign = 1;
 
    else if(inString[0] == '*')
        sign = 2;
    else
        sign = 3;
 
    /*The operation down there is to splite the whole string into separate term*/
    /*the term is split by detecting the sign*/
 
    for(i=0; i < length; i++)
    {
      /*pass if char not '+' and not '-' and current pos is not the end of the string*/
        if(inString[i] != '+' && inString[i] != '-' && inString[i] != '*' && inString[i] != '/' && i != length-1)
        {
 
            tempString = (char*)realloc(tempString,sizeof(char)*j+1);
            tempString[j] = inString[i];
            j++;
            continue;
        }
        else
        {    
          /*to add the last value before the end of the string*/
            if(i == length-1)
            {
                    tempString = (string)realloc(tempString,sizeof(char)*j+1);
                    tempString[j] = inString[i];
                    j++;
            }
 
            if(j != 0)
            {
              /*save the term into expression format*/
                if((*inExp)->numberOfTerms == 0)
                    (*inExp)->exp = (xContainer*)calloc(3,sizeof(xContainer));
                else
                    (*inExp)->exp = (xContainer*)realloc((*inExp)->exp,sizeof(xContainer)*((*inExp)->numberOfTerms+1));
 
 
                (*inExp)->exp[(*inExp)->numberOfTerms] = splitTerm(tempString,sign,j);
                (*inExp)->numberOfTerms++;
 
                if(inString[i] == '-')
                    sign = 0;
 
                else if(inString[i] == '+')
                    sign = 1;
 
                else if(inString[i] == '*')
                    sign = 2;
 
                else
                    sign = 3;
 
            }
            j = 0;
            tempString = (string)realloc(tempString,sizeof(char)*0);
        }
    }
}
 
/*function to handle term*/
xContainer splitTerm(string inTerm,int inSign, int length)
{
    string tempString;
    xContainer part;
    int xFlag=0,powerFlag=0;
    int i,j=0;
 
    part = (xContainer)malloc(sizeof(struct terms));
    part->KnowX = 0;
    part->positive = inSign;
    part->isX = 0;
    part->x_power = 1;
    part->x_times = 1;
    part->x_value = 0;
 
    tempString = (string)calloc(1,sizeof(char));
 
    /*function below is to determine x and square root*/
    for(i=0; i < length; i++)
    {
        if(inTerm[i] != 'x' && inTerm[i] != '^')
        {
            tempString = (string)realloc(tempString,sizeof(char)*j+1);
            tempString[j] = inTerm[i];
            j++;
 
            if(i == length-1 && !xFlag && !powerFlag)
            {
                part->x_value = atof(tempString);
                part->KnowX = 1;
            }
            continue;
        }
        else
        {
            if(inTerm[i] == 'x' && strlen(tempString) > 0)
            {
                part->x_times = atof(tempString);
                xFlag = 1;            
            }
            else if(inTerm[i] == 'x')
                xFlag = 1;
 
            if(inTerm[i] == '^')
            {
                powerFlag = 1;
                if(!xFlag)
                    part->x_value = atof(tempString);
            }
 
            j = 0;
            tempString = (string)realloc(tempString,sizeof(char)*0);
 
        }    
    }
 
    if(xFlag)
    {
        part->isX = 1;
        part->KnowX = 0;
    }
 
    if(powerFlag)
        part->x_power = atof(tempString);
 
    switch(inSign)
 
        case 0:
        case 1:
        case 2:
        case 3:
 
 
    return part;
 
 
}

With this code i am able to capture expression like 3x+9x^2-2/7..something like that...So i am wondering if i want to have some like (((x-3)+(x+9))(x+6)) or (x+3)(3x-9)(4-x)....The figure can be anything up to the user... So how am i goin to write the code?

[cool17]

can someone help with it? I am trying to get my code going... thank thank

[Banfa]

Give a more precise description of your problem. Why will your code capture the first expression successfully but not the second?