Question

ASSIGNMENT: A7 - Student Line Up "Student Line Up", page 295, Number 14 A teacher has asked all students to line up single file according to their first name. For example, in one class Amy will be in the front of the line and Yolanda will be at the end. Write a program that prompts the user to enter the number of students in the class, then loops to read in that many names. Once all the names have been read in, it reports which student is in the front of the line and which student is at the end of the line. You may assume that no two students have the same name. This is not a sorting assignment. Input Validation: Do not let the user enter a number less than 1 of greater than 25 for the number of students. EXTRA CREDIT: even though you do not have to sort this array, just tell who is first and who is last in line, if you sort it and then tell me who is first and who is last based on the sorted names, you will receive extra credit (hint, your text covers sorting, there are several ways to do this). (You will receive an extra 1 point if you can do this).

I would love it if someone would make this code from scratch.. not copied from somewhere else. I just want this explained and how it is done. The extra credit would be nice too..

This is C++

Answer 1

//For any queries, feel free to comment.

// The following code is with the sorting algorithm for extra credit.

// The following code uses QuickSort to sort the array. If you want more details on sorting, comment below.

**CODE**

#include <bits/stdc++.h>
using namespace std;

int partition (string arr[], int low, int high)
{
    int i = low - 1;
  
    //Pivot = element whose correct
    //position we want to find
    string pivot = arr[high];
  
    //Find correct position by looping
    for (int j = low; j <= high - 1; j++)
    {
        // If current element is smaller than the pivot
        if (arr[j] < pivot)
        {
            i++;
            swap(arr[i], arr[j]);
        }
    }
  
    swap(arr[i + 1], arr[high]);
    return (i + 1);
}

//Main quickSort function
void quickSort(string arr[], int low, int high)
{
    if (low < high)
    {
        //Find correct position of one element at a time.
        int pi = partition(arr, low, high);
      
        //Leaving pi and sort remaining arrays by
        //dividing it into two parts
        quickSort(arr, low, pi - 1);
        quickSort(arr, pi + 1, high);
    }
}

int main()
{
    int n;
    cout<<"Enter number of students: ";
    cin>>n;
  
    string arr[n];
  
    for(int i=0;i<n;i++)
        cin>>arr[i];

    quickSort(arr,0,n-1);
  
    cout<<"First position: "<<arr[0]<<"\n";
    cout<<"Last position: "<<arr[n-1]<<"\n";
    return 0;
}

**SNIPPET**

**OUTPUT**