Question

C++

Part1: Palindrome detector

Write a program that will test if some string is a palindrome

1. Ask the user to enter a string
2. Pass the string to a Boolean function that uses recursion to determine if something is a palindrome or not. The function should return true if the string is a palindrome and false if the string is not a palindrome.
3. Main displays the result ( if the string is a palindrome or not

Part 2: Compute the Greatest Common Factor

Write a program that computes the GCF (Greatest Common Factor) of two positive whole numbers entered by the user. For example the GCF of 24 and 18 is 6. The program will prompt the user for entering two positive whole numbers and will then return their GCF. The user may terminate the program by entering -1 for the first number. The program should provide a recursive function to compute GCF.

Test the above for at least 4 pairs of values.

Mathematical Calculation:

GCF of two whole numbers can be calculated mathematically via repeated division. For example, GCF of 16 and 26 can be found as below:

1. Divide 16 into 26. The remainder is 10.

2. Divide 10 (the remainder in the last step) into 16 (the divisor in the last step). The remainder is 6.

3. Divide 6 (the remainder in the last step) into 10 (the divisor in the last step). The remainder is 4.

4. Divide 4 (the remainder in the last step) into 6 (the divisor in the last step). The remainder is 2.

5. Divide 2 (the remainder in the last step) into 4 (the divisor in the last step). The remainder is 0. Hence GCF is 2.

Note: You are to provide a recursive function to implement the above algorithm.

Answer 1

Note: Could you plz go through this code and let me know if u need any changes in this.Thank You
_________________

// Part#1:

#include <iostream>

#include <cctype>

using namespace std;

//function declarations

bool testPalindrome(string str);

string upperCaseIt(string s);

int main()

{

//Declaring variables

string str,str1;

char ch;

  

/* This while loop continues to execute

* until the user enters other than 'y' or 'Y'

*/

while(true)

{

str1="";

//Getting the input entered by the user

cout<<"\nEnter a string :";

getline(cin,str);

  

//eliminating spaces,commas..etc

for(int i=0;i<str.length();i++)

{

if(isalpha(str[i]))

str1+=str[i];

}

//calling the function

str1=upperCaseIt(str1);

//calling the function

if(testPalindrome(str1))

cout<<"This is a Palindrome"<<endl;

else

cout<<"This is not a Palindrome"<<endl;  

cout<<"\nDo you Want to continue(Y/N):";

cin>>ch;

if(ch=='y'||ch=='Y')

{

cin.ignore();

continue;

}else

{

break;

}

}

return 0;

}

/* This is a recursive function which calculates

* whether the String is Palindrome or not using recursive method

* Param:string

* return: boolean

*/

bool testPalindrome(string str) {

if(str.length() == 0 || str.length() == 1)

return true;

else if(str[0] == str[str.length()-1])

return testPalindrome(str.substr(1, str.length()-2));

  

return false;

}

// This function will convert the lower case to upper case

string upperCaseIt(string s)

{

for (int i = 0; i < s.size(); i++)

{

if (s.at(i) >= 97 && s.at(i) <= 122)

{

s.at(i) = s.at(i) - 32;

}

}

return s;

}

_____________________

Output:

_____________________________

// Part#2:

#include <iostream>
#include <iomanip>
using namespace std;
//Function Declarations
void getInput(int &a,int &b);
int gcf(int a,int b);
void display(int a,int b,int res);
int main(){
int a,b;
//Calling the functions

while(true)
{
getInput(a,b);
int res=gcf(a,b);
display(a,b,res);
  
}

  
return 0;
  
}
//This function will get the valid user inputs
void getInput(int &a,int &b)
{
while(true)
{
cout<<"\nEnter a:";
cin>>a;
if(a==-1)
{
   exit(0);
       }
else if(a<=0)
{
cout<<"Invalid.Must be >=0"<<endl;
}
else
break;
}
  
while(true)
{
cout<<"Enter b:";
cin>>b;
if(b<=0)
{
cout<<"Invalid.Must be >=0"<<endl;
}
else
break;
}
  
  
}
//This function will calcluate the gcd of two numbers
int gcf(int num1,int num2)
{
// % is modulus which is the remainder of a division
// base case
if ((num1 % num2) == 0) {
return num2;
}
// recursive case
else {
return gcf(num2, num1 % num2);
}
}
//This function will display the output
void display(int a,int b,int res)
{
cout<<"The GCF of "<<a<<" and "<<b<<" is :"<<res<<endl;
}
____________________________

Output:

_______________Could you plz rate me well.Thank You