// functions tesing for palindrome
// Walt Savitch 
// 03/09/00

#include "palindrome.h"

// returns true if string is palindrome
bool isPal(const string& tocheck){
    const string punctuation(",;:.?!'\" ");  //punctuation to remove
    string str = removePunct(tocheck, punctuation);
    str = makeLower(str);
    return (str == reverse(str));
}

//returns a copy of src with characters in punct removed
string removePunct(const string& src, 
	const string& punct){

     string tmp(src);
     int src_len = src.length();

     // loop through string until all
     // punctuation symbols removed

     int location = tmp.find_first_of(punct); 

     while(location != string::npos){
  	tmp.erase(location,1);
	location = tmp.find_first_of(punct);
     }

     return tmp;
}


// lowers the case of string, returns lower case
string makeLower(const string& s) {

    string tmp;
    int slength=s.length();
    char c;

    for (int i = 0; i < slength; i++)
        tmp += tolower(s[i]);
    return tmp;
}


// reverses the string, retruns reversed
string reverse(const string& str){

   string tmp(str);

   int start = 0;
   int end = tmp.length()-1;
   for( ;start < end; start++, end--)
	swap(tmp[start], tmp[end]);

   return tmp;
}

// swaps the characters
void swap(char& lhs, char& rhs)
{
   char tmp = lhs;
   lhs = rhs;
   rhs = tmp;
}