Multi part question thank you! c++

Part A: Define a struct for a Circle with a radius, circumference, area. Then define an array with 10 Circles. Input the radius for each circle from the user (and also set its circumference, area). Then output the area of the largest circle in the array.

Part B : If the program answers "yes" to the previous question, meaning the two strings are permutations of each other, determine if each string has all unique characters

FOR PART B:

/* function to check whether two strings are

Permutation of each other */

bool arePermutation()

{

string str1, str2;

cout << "Enter str1: ";

getline(cin, str1);

cout << "Enter str2: ";

getline(cin, str2);

// Get lenghts of both strings

int n1 = str1.length();

int n2 = str2.length();

// If length of both strings is not same,

// then they cannot be Permutation

if (n1 != n2)

return false;

// Sort both strings

sort(str1.begin(), str1.end());

sort(str2.begin(), str2.end());

// Compare sorted strings

for (int i = 0; i < n1; i++)

if (str1[i] != str2[i])

return false;

return true;

}