I'm trying to extract the value of the coeffecients and the exponent from a polynomial. I have already succeeded in extracting the coeffients using strtok. I applied the same concept to find the exponent, but I don't know how to use strtok to extract the string AFTER the delimiters or skip the first character, and strtok is the only extracting tool I know. The program is developed in C++ but strtok uses c codes so I just post it here
This is main()
#include <iostream>
#include <cctype>
#include <cstring>
#include <cstdlib>
#include <string>
using namespace std;
void extractCoeff (char *str, char *copy);
void extractExp (char *str, char *copy);
int main()
{
const int SIZE = 150; // size for string input
char *string;
string = new char[SIZE];
cout << "Enter the polynomial\n";
cin.ignore();
cin.getline(string, SIZE);
char *strCopy;
strCopy = new char[SIZE];
strcpy(strCopy, string);
char *copy1;
copy1 = new char[SIZE];
strcpy(copy1, string);
extractCoeff(string, copy1);
cout << endl << endl;
char *copy2;
copy2 = new char[SIZE];
strcpy(copy2, strCopy);
extractExp(strCopy, copy2);
return 0;
}
extracting coeff
void extractCoeff (char *str, char *copy)
{
char *p = strtok(str, " +"); // extract the first time
char *search;
int counter = 0;
while (p)
{
search = strstr(p, "x^");
cout << "Token: " << p << endl;
cout << "Search " << search << endl;
p = strtok(NULL, " +");
counter++;
}
cout << copy << endl;
// find coeff
int *coefficient;
coefficient = new int[counter];
p = strtok(copy, " +"); // extract the second time to find coeff
int a = 0;
while (p)
{
cout << "p: " << p << endl;
long coeff;
if (*p == 'x')
{
coeff = 1;
}
else if (*p == NULL)
{
coeff = 0;
}
else
{
char *endptr;
coeff = strtol(p, &endptr, 10);
}
coefficient[a] = coeff;
p = strtok(NULL, " +");
a++;
}
for (int i = 0; i < counter; i++)
cout << coefficient[i] << endl;
}
extracting exponent (it prints also the + characters, i just want the exponents)
void extractCoeff (char *str, char *copy)
{
char *p = strtok(str, " +"); // extract the first time
char *search;
int counter = 0;
while (p)
{
search = strstr(p, "x^");
cout << "Token: " << p << endl;
cout << "Search " << search << endl;
p = strtok(NULL, " +");
counter++;
}
cout << copy << endl;
// find coeff
int *coefficient;
coefficient = new int[counter];
p = strtok(copy, " +"); // extract the second time to find coeff
int a = 0;
while (p)
{
cout << "p: " << p << endl;
long coeff;
if (*p == 'x')
{
coeff = 1;
}
else if (*p == NULL)
{
coeff = 0;
}
else
{
char *endptr;
coeff = strtol(p, &endptr, 10);
}
coefficient[a] = coeff;
p = strtok(NULL, " +");
a++;
}
for (int i = 0; i < counter; i++)
cout << coefficient[i] << endl;
}
void extractExp (char *str, char *copy)
{
char *p = strtok(str, " x^"); // extract the first time
//char *search;
int counter = 0;
while (p)
{
//search = strstr(p, "x^");
//cout << "Token: " << p << endl;
//cout << "Search " << search << endl;
p = strtok(NULL, " x^");
counter++;
}
cout << copy << endl;
// find coeff
int *exp;
exp = new int[counter];
p = strtok(copy, " x^"); // extract the third time
int b = 0;
while (p)
{
cout << "p2: " << p << endl;
int expVal;
if (*p == NULL)
{
expVal = 0;
}
else
{
char *endptr;
expVal = strtol(p, &endptr, 10);
}
exp[b] = expVal;
p = strtok(NULL, " x^");
b++;
}
for (int i = 0; i < counter; i++)
cout << exp[i] << endl;
}
