Question

Palindrome is a word or a phrase when taken in reverse order, gives the same word or phrase. For example, the word “radar” is a palindrome. The phrase "Do geese see God?" is also a palindrome after the removal of the question mark and all the spaces and the conversion of the remaining alphabets to either upper or lower case.

Write a program that uses an STL stack to check if an arbitrary string containing multiple words separated by spaces (do not use a single word to test your program!) is a palindrome. You may use either a C-string and/or a C++ string to store the word or phrase to be tested. Besides the main() function, the program must include the following additional functions:

• inputString, which prompts the user to enter a phrase (instead of just a word) and store it in a string object
• convert2lower, which a) removes punctuation and blank characters in the string and b) converts all alphabets in the string to lower case
• isPalindrone, which checks the converted input string to determine if it is a palindrome. It returns true or false depending on whether the string is or is not a palindrome.

The following websites provide useful information related to the above problem:

http://www.tutorialspoint.com/ansi_c/c_function_references.htm

http://www.cplusplus.com/reference/string/string/

http://www.cplusplus.com/reference/stack/stack/

https://en.wikipedia.org/wiki/Palindrome

Note: The file you turned in must contain a) properly documented source code plus b) screen capture of the program output.

Answer 1

Program

#include<iostream>
#include<string.h>
#include <bits/stdc++.h>

using namespace std;

// function to prompts the user to enter a phrase
//and store it in a string object
void inputString(string &phrase)
{
//prompts the user to enter a phrase
cout << "Enter a phrase: ";
//read the phrase
getline(cin, phrase);
}

//function to removes punctuation and blank characters in the
//string and converts all alphabets in the string to lower case
string convert2lower(string phrase)
{
string str = "";
for(int i=0; i<phrase.size(); i++)
{
//skipping space and punctuation
if(ispunct(phrase[i]) || isspace(phrase[i]))
continue;
//convert to lower case
str = str + (char)(tolower(phrase[i]));
}
return str;
}

//function to return whether the phrase is a Palindrome
bool isPalindrone(string phrase)
{
stack <char> s;
int i;
int mid = phrase.size()/2;
for(i=0; i<mid; i++){
s.push(phrase[i]);
}

if(phrase.size()%2!=0)
i++;

for(;i<phrase.size(); i++)
{
char ch = s.top();
if(ch!=phrase[i])
return false;
s.pop();
}

return true;
}

//main function
int main()
{
string phrase, str;
bool fg;

//read the phrase
inputString(phrase);

//removes punctuation, blank characters and converts to lower case
str = convert2lower(phrase);

//check whether the phrase is a Palindrome
fg = isPalindrone(str);

if(fg)
cout<<"\""<<phrase<<"\" "<< "is a Palindrome"<<endl;
else
cout<<"\""<<phrase<<"\" "<< "is not a Palindrome"<<endl;

return 0;
}

Output:

Enter a phrase: able was i ere i saw elba
"able was i ere i saw elba" is a Palindrome

Enter a phrase: a man a plan a canal panama
"a man a plan a canal panama" is a Palindrome

Enter a phrase: Do geese see God
"Do geese see God" is a Palindrome

Enter a phrase: good bye!
"good bye!" is not a Palindrome

N.B.  Whether you face any problem then share with me in the comment section, I'll happy to help you.