/*
 * Use the recursion and the stack ADT to reverse a list of characters
 */
#include <iostream>
#include "C6-StackA.h"
using namespace std;

void revStack(string str);
void revRecursion(string str, int index);

int main()
{
  string str;

  cout << "Enter a string of characters: ";
  cin >> str;

  // Check for empty string
  if(str.length() == 0)
    return 0;
  
  // Reverse using recursion
  cout << "Using recursion, the reverse string is: ";
  revRecursion(str, 0);
  cout << endl;

  // Reverse using Stack ADT
  cout << "Using stack ADT, the reverse string is: ";
  revStack(str);
  cout << endl;
  
  return 0;
}

/*
 * Recursive routine to reverse string
 */
void revRecursion(string str, int index)
{
  if(index < str.length())
    revRecursion(str, index+1);

  cout << str[index];
}

/*
 * Use stack to reverse string
 */
void revStack(string str)
{
  Stack stklist;
  char c;
  
  // push each character on the LIFO stack
  for(int i=0 ; i<str.length() ; i++)
    stklist.push(str[i]);

  // pop the items from the stack in LIFO order and display them
  while(!stklist.isEmpty()){
    stklist.pop(c);
    cout << c;
  }
}