Question

Using the string functions below, write new functions to do the following, and test them in your main() function:

• Determine whether the first or last characters in the string are any of the characters a, b, c, d, or e.
• Reverse a string
• Determine whether a string is a palindrome (spelled the same way forward or backward

FUNCTIONS REFERENCE:

string myString = "hello"; // say we have a string…

// … we can call any of the following

// string member functions on it.

myString[x] // get element at position x

myString.back() // get last element

myString.front() // get first element

myString.substr(first, last) // get a substring of the string, from index first to index last.   // (including first, not including last)

myString. find(str) // find the index of the first occurrence of str in the string.

// (can also use a character rather than a string for the parameter)

(not member functions, but useful)

toupper(str) // convert the string str to uppercase

tolower(str) //….      lowercase

What I have so far:

#include <iostream>
#include "string"
using namespace std;

bool checkFirstAndLast(string myString, char characterCheck)
{
if(myString.front() == characterCheck && myString.back() == characterCheck)
return true;
else
return false;
  
}

int main()
{
char lettersToCheck[5]=
{
'a','b','c','d','e'
};
  
string something = "buuperb";
bool firstEqLast=false;
  
for(int i=0;i<5;i++)
{
if (checkFirstAndLast(something, lettersToCheck[i]))
firstEqLast=true;
  
  
}
  
cout<< checkFirstAndLast(something,'a') <<endl;
cout<< checkFirstAndLast(something,'b') <<endl;
cout<< checkFirstAndLast(something,'c') <<endl;
cout<< checkFirstAndLast(something,'d') <<endl;
cout<< checkFirstAndLast(something,'e') <<endl;
  
return 0;
}

Language is in C++

Answer 1

Code

#include <iostream>
#include <string>
using namespace std;

bool checkPalindrome(string myString)
{
   int i = 0;
   int j = myString.length() - 1; // j will be having last character index
  
   while (i < j)
   {
       if (toupper(myString[i]) != toupper(myString[j])) // toupper for case insensitive comparison
           return false;
       i++;
       j--;
   }
   return true;
}

string reverseString(string myString)
{
   int i = 0;
   int j = myString.length() - 1; // j will be having last character index

   while (i < j)
   {
       char temp = myString[j];
       myString[j] = myString[i];
       myString[i] = temp;
       i++;
       j--;
   }
   return myString;
}

bool checkFirstAndLast(string myString, char characterCheck)
{
   if (myString.front() == characterCheck && myString.back() == characterCheck)
       return true;
   else
       return false;
}

int main()
{
   char lettersToCheck[5] =
   {
       'a','b','c','d','e'
   };

   string something = "buuperb";
   bool firstEqLast = false;

   for (int i = 0; i<5; i++)
   {
       if (checkFirstAndLast(something, lettersToCheck[i]))
           firstEqLast = true;
   }

   cout << "String \"buuperb\" has 'a' as first and last character: "<<checkFirstAndLast(something, 'a') << endl;
   cout << "String \"buuperb\" has 'b' as first and last character: "<< checkFirstAndLast(something, 'b') << endl;
   cout << "String \"buuperb\" has 'c' as first and last character: " << checkFirstAndLast(something, 'c') << endl;
   cout << "String \"buuperb\" has 'd' as first and last character: " << checkFirstAndLast(something, 'd') << endl;
   cout << "String \"buuperb\" has 'e' as first and last character: " << checkFirstAndLast(something, 'e') << endl;

   // Palindrome test cases
   cout << "String \"Hello\" is Palindrome: " << checkPalindrome("Hello")<< endl;
   cout << "String \"ABCDEDCBA\" is Palindrome: " << checkPalindrome("ABCDEDCBA") << endl;
   cout << "String \"geeks\" is Palindrome: " << checkPalindrome("geeks") << endl;
   cout << "String \"Radar\" is Palindrome: " << checkPalindrome("Radar") << endl;

   // String Reverse test cases
   cout << "Reverse string for \"Hello\" is: " << reverseString("Hello") << endl;
   cout << "Reverse string for \"ABCDEDCBA\" is: " << reverseString("ABCDEDCBA") << endl;
   cout << "Reverse string for \"geeks\" is: " << reverseString("geeks") << endl;
   cout << "Reverse string for \"Radar\" is: " << reverseString("Radar") << endl;

   return 0;
}

Test Output