Question

Hi, I need to change the conversion where stack is into a class stack and add a template <class type>

PROMPT:

write a program that reads a string consisting of a positive integer
or a positive decimal number and converts the number to the numeric format.
if the string consists of a decimal number, the program must use a stack to convert the decimal number to the numeric format.

#include
#include
#include
#include
#include

using namespace std;
double conversion(string);

int main() {
   int num = 0, abc;
   string str;

   cout << "Enter the string: ";
   cin >> str;
   cout << "String is: " << str;

   //wrong input
   int i;
   for (i = 0; str[i] != '\0'; i++)
   {
       if ((str[i] < 48 || str[i]>57) && str[i] != '.')
           throw str;
   }

   // decimal number
   for (int i = 0; str[i] != '\0'; i++)
   {
       if (str[i] == '.')
       {
           num = 1;
           break;
       }
   }
   if (num == 0)
   {
       abc = stoi(str);
       cout << endl << "Number is: " << abc;
   }
   else {
       double decimal_abc = conversion(str);
       cout << "Number is: " << decimal_abc;
   }
   system("pause");
   return 0;
}
//conversion
double conversion(string str)
{
   stack < int> stk;
   int n = str.length();
   char *s;
   s = new char[n];

   int k = 0;
   bool decimal = false;

   for (int i = n - 1; i >= 0; i--)
   {
       if (str[i] == '.')
       {
           decimal = true;
       }
       stk.push(str[i]);
   }
   cout << endl;

   while (!stk.empty())
   {
       s[k] = stk.top();
       stk.pop();
       k++;
   }
   cout << endl;
   return stod(s);
}

Answer 1

Conversion.cpp:

#include<iostream>
#include<string>
#include <cstdlib>
#define SIZE 100
// define default size of stack
using namespace std;

// Class for stack
template <class type>
class stack
{
    type *array;
    int top_element;
    int capacity;

public:
    stack(int size = SIZE);
    void push(type);
    type pop();
    type top();
    bool empty();
    bool isFull();
};
// Constructor to initialize stack
template <class type>
stack<type>::stack(int size)
{
    array = new type[size];
    capacity = size;
    top_element = -1;
}

// function to add an element x of "type" may be int,char etc.. data type in the stack
template <class type>
void stack<type>::push(type x)
{
    if (isFull())
    {
        cout << "Stack OverFlow\nProgram Terminated\n";
        exit(EXIT_FAILURE);
    }

    cout << endl << "Inserting element " << x<<" into the stack.";
    array[++top_element] = x;
}

// function to pop top element from the stack
template <class type>
type stack<type>::pop()
{
    // check for stack underflow
    if (empty())
    {
        cout << "UnderFlow\nProgram Terminated\n";
        exit(EXIT_FAILURE);
    }

    cout << endl<< "Removing element " << top() <<" from the stack. ";

    // decrease stack size by 1 and return the popped element
    return array[top_element--];
}

// function to return top element in the stack
template <class type>
type stack<type>::top()
{
    if (!empty())
        return array[top_element];
    else
        exit(EXIT_FAILURE);
}
template <class type>
bool stack<type>::empty()
{
    return top_element == -1;   //returns true or false for stack is empty or not
}
template <class type>
bool stack<type>::isFull()
{
    return top_element == capacity - 1;   //returns true or false for stack is full or not
}
double conversion(string);

int main() {
    int num = 0, abc;
    string str;

    cout << "Enter the string: ";
    cin >> str;
    cout << "String is: " << str;

    //wrong input
    int i;
    for (i = 0; str[i] != '\0'; i++)
    {
        if ((str[i] < 48 || str[i]>57) && str[i] != '.')
            throw str;
    }

    // decimal number
    for (int i = 0; str[i] != '\0'; i++)
    {
        if (str[i] == '.')
        {
            num = 1;
            break;
        }
    }
    if (num == 0)
    {
        abc = stoi(str);
        cout << endl << "Number is: " << abc<<endl;
    }
    else {
        double decimal_abc = conversion(str);
        cout << endl<< "Number is: " << decimal_abc<< endl;
    }
    //system("pause");
    return 0;
}
//conversion
double conversion(string str)
{
    stack < char> stk;
    int n = str.length();
    char *s;
    s = new char[n];

    int k = 0;
    bool decimal = false;

    for (int i = n - 1; i >= 0; i--)
    {
        if (str[i] == '.')
        {
            decimal = true;
        }
        stk.push(str[i]);
    }
    cout << endl;

    while (!stk.empty())
    {
        s[k] = stk.top();
        stk.pop();
        k++;
    }
    cout << endl;
    return stod(s);
}

Output:

I added print statements in push(type) and pop function for better understanding.You can delete them if you don't want.

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