Question

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.

Answer 1

Answer:

#include <iostream>

#include <string>

#include <stack>

#include <math.h>

using namespace std;

int main() {

  string s;

  double n=0;

  int position=0;  

  stack<int> wholeNumbers;

  cout<<"Enter a decimal number:";

  cin>>s;

  string::iterator counter = s.begin();

  while(*counter!='.' && counter!=s.end()){

      wholeNumbers.push(*counter-48);

      counter++;

      position=position+1;

     

  }

  for(int i=0;i<position;i++){

      n=n+(wholeNumbers.top()*pow(10,i));

      wholeNumbers.pop();

  }

  position=-1;

  if(counter!=s.end()){

      counter++;

  }

  while(counter!=s.end()){

      n=n+((*counter-48)*pow(10,position));

      position=position-1;

      counter++;      

  }

  cout<<n;

}

Explanation:

• Inside the while loop, push the push a number to the wholeNumbers stack by subtracting it with 48.
• Increment the counter and position variable by 1 inside the while loop.
• Count the number of digit, push each digit to top of stack and find the end of the number,
• Run a for loop up to the value of position variable and pop a value from the wholeNumbers stack.