Question

hello, this is my C++ programm and I need help for this two question. how can i implement the two questions in my code

Write a recursive function template quicksort that takes a container of type T (T is, for example, array <int, 1000> or vector <string>) as a parameter and applies the algorithm described to the container so that it is not sorted in descending order. The function template should receive the container object, an initial index and an end index as arguments.

Another function template partition is to be called by quicksort to carry out the partitioning step. Test the result of your sorting by sorting an array <int, 1000> filled with random values and then a vector <string> filled with at least five words in an unsorted order and checking the sorting results with lessEqualSorted.

#include<iostream>

using namespace std;

//partition function

int partition(int arr[], int left, int right) {

    //initial value left

    int indexOfPivot = left;

    int i;

    //label to go back and repeat two steps

label:

    //firstr step

    i = right;

    //finding smaller or equal element

    while (i > indexOfPivot&& arr[i] > arr[indexOfPivot])

        i--;

    if (i == indexOfPivot)

        return indexOfPivot;

    swap(arr[indexOfPivot], arr[i]); //swapping

    indexOfPivot = i;

    //second step

    i = left;

    ////finding greater element

    while (i < indexOfPivot && arr[i] <= arr[indexOfPivot])

        i++;

    if (i == indexOfPivot)

        return indexOfPivot;

    swap(arr[indexOfPivot], arr[i]); //swapping

    indexOfPivot = i;

    goto label; //repeating step1 and 2

}

//recursive function

void qsort(int arr[], int start, int end) {

    if (start < end) {

        int p = partition(arr, start, end);

        qsort(arr, start, p - 1);   //left half sorting

        qsort(arr, p + 1, end); //right half sorting

    }

}

int main() {

    //testing quicksort

    int arr[] = { 16,17,18,7,6,9,14,1,15,16,7,10,1,19,13,18,9,7,7,9 }; //ist von chegg

    //int arr[] = { 75, 70, 65, 68, 98, 78, 100, 93, 55, 61, 81, 84 };

    int n = 20;

    //int n = 1000;

    cout << "Before Sorting: \n";

    for (int i = 0; i < n; i++) {

        cout << arr[i] << " ";

    }

    qsort(arr, 0, n - 1);

    cout << "\nAfter Sorting: \n";

    for (int i = 0; i < n; i++) {

        cout << arr[i] << " ";

    }

    cout << endl;

}

Answer 1

#include<iostream>
using namespace std;

//partition function
template <class T>
int partition(T arr[], int left, int right) {
//initial value left
int indexOfPivot = left;
int i;

//label to go back and repeat two steps
label:

//firstr step
i = right;

//finding smaller or equal element
while (i > indexOfPivot&& arr[i] > arr[indexOfPivot])
i--;
if (i == indexOfPivot)
return indexOfPivot;
swap(arr[indexOfPivot], arr[i]); //swapping
indexOfPivot = i;

//second step
i = left;

////finding greater element
while (i < indexOfPivot && arr[i] <= arr[indexOfPivot])
i++;
if (i == indexOfPivot)
return indexOfPivot;
swap(arr[indexOfPivot], arr[i]); //swapping
indexOfPivot = i;
goto label; //repeating step1 and 2
}

//recursive function
template <class T>
void qsort(T arr[], int start, int end) {
if (start < end) {
int p = partition(arr, start, end);
qsort(arr, start, p - 1); //left half sorting
qsort(arr, p + 1, end); //right half sorting
}
}

int main() {
//testing quicksort
int arr1[] = { 16,17,18,7,6,9,14,1,15,16,7,10,1,19,13,18,9,7,7,9 }; //ist von HomeworkLib
int n = 20;
//int n = 1000;
cout << "Before Sorting: \n";
for (int i = 0; i < n; i++) {
cout << arr1[i] << " ";
}
qsort(arr1, 0, n - 1);
cout << "\nAfter Sorting: \n";
for (int i = 0; i < n; i++) {
cout << arr1[i] << " ";
}
cout << endl;

int arr2[] = { 75, 70, 65, 68, 98, 78, 100, 93, 55, 61, 81, 84 };
n = 12;

cout << "Before Sorting: \n";
for (int i = 0; i < n; i++) {
cout << arr2[i] << " ";
}
qsort(arr2, 0, n - 1);
cout << "\nAfter Sorting: \n";
for (int i = 0; i < n; i++) {
cout << arr2[i] << " ";
}
cout << endl;

char arr3[] = {'j' , 'a' , 'i'};
n = 3;

cout << "Before Sorting: \n";
for (int i = 0; i < n; i++) {
cout << arr3[i] << " ";
}
qsort(arr3, 0, n - 1);
cout << "\nAfter Sorting: \n";
for (int i = 0; i < n; i++) {
cout << arr3[i] << " ";
}
cout << endl;

string arr4[] = {"jai" , "sethia" , "jain"};
n = 3;

cout << "Before Sorting: \n";
for (int i = 0; i < n; i++) {
cout << arr4[i] << " ";
}
qsort(arr4, 0, n - 1);
cout << "\nAfter Sorting: \n";
for (int i = 0; i < n; i++) {
cout << arr4[i] << " ";
}
cout << endl;
}