Question

C++ I need a program that will read a list of names from a data file and store them in an array. You will then sort the array by last name using a quicksort, and display the results, one name per line.Each line has a first name and a last name.The file has 40 names in it right now, but the array should be able to accommodate up to 50

names.txt*****************************************************

Barbara Wright
Ian Chesterton
Steven Taylor
Sara Kingdom
Dodo Chaplet
Ben Jackson
Jamie McCrimmon
Victoria Waterfield
Zoe Heriot
Liz Shaw
Jo Grant
SarahJane Smith
Harry Sullivan
Kay Nine
Tegan Jovanka
Nyssa Traken
Kam Elion
Perpugilliam Brown
Melanie Bush
Ace McShane
Grace Holloway
Lucie Miller
Charlotte Pollard
Rose Tyler
Jack Harkness
Mickey Smith
Donna Noble
Martha Jones
Astrid Peth
Wilfred Mott
Amy Pond
Rory Williams
River Song
Craig Owens
Clara Oswald
Paternoster Gang
Bill Potts
Graham O'Brien
Ryan Sinclair
Yasmin Khan

**********************************************************************************************

Answer 1

INPUT
#######

Input file name used is input.txt

names Notepad File Edit Format View Help Barbara Wright IanChesterton Steven Taylor Sara Kingdom Dodo Chaplet Ben Jackson Jamie McCrimmon Victoria Waterfield Zoe Heriot Liz Shaw 3o Grant SarahJane Smith Harry Sullivan Kay Nine Tegan Jovanka Nyssa Traken Kam Elion Perpugilliam Brown Melanie Bush Ace McShane Grace Holloway Lucie Miller Charlotte Pollard Rose Tyler Jack Harkness Mickey Smith Donna Noble Martha Jones Astrid Peth WilfredMott Amy Pond

//####################### PGM START ########################################

#include<iostream>
#include<fstream>

using namespace std;

//function to partition the array of strings and sort it
int partition (string first[],string last[], int low, int high) {
  
   string pivot = last[high];    // pivot
    int i = (low - 1); // Index of smaller element

    for (int j = low; j <= high- 1; j++)
    {
        // If current element is smaller than or
        // equal to pivot
        if (last[j] <= pivot)
        {
            i++;    // increment index of smaller element
          
            //swaping last names
            string temp=last[i];
            last[i]=last[j];
            last[j]= temp;
          
            //swaping first names
            temp=first[i];
            first[i]=first[j];
            first[j]=temp;
          
        }
    }
    //swaping last names
    string temp=last[i+1];
    last[i+1]=last[high];
    last[high]= temp;
          
    //swaping first names
    temp=first[i+1];
    first[i+1]=first[high];
    first[high]=temp;
    return (i + 1);
}
//function to do the quicksorting of names based on last name
void quickSort(string first[],string last[],int low, int high)
{
    if (low < high)
    {
        int pi = partition(first, last, low, high);
        quickSort(first, last, low, pi - 1);
        quickSort(first, last, pi + 1, high);
    }
}
//function to print the names
void printNames(string first[], string last[], int size)
{
    int i;
    for (i=0; i < size; i++)
        cout<<first[i]<<" "<<last[i]<<"\n";
}
//main method
int main(){
   string firstname[50],lastname[50];
   int n=0;
  
   ifstream infile;
   infile.open("names.txt");
  
   if(infile.bad()){
       cout<<"Cant open names.txt file or file does not exist\n";
   }else{
      
       while((infile>>firstname[n]>>lastname[n]) && n<50){
           n+=1;
       }
   }
   quickSort(firstname,lastname,0,n-1);
   printNames(firstname,lastname,n);
  
   return 0;
}

//################################### PGM END ################################

OUTPUT
########

C:\UsersJijinAVA Documents\Dev Perpugilliam Brown Melanie Bush Dodo Chaplet Ian Chesterton Kam Elion Paternoster Gang JoGrant Jack Harkness Zoe Heriot Grace Holloway Ben Jackson Martha Jones Tegan Jovanka Yasmin Khan Sara Kingdom Jamie McCrimmon Ace McShane Lucie Miller Wilfred Mott Kay Nine Donna Noble Graham O'Brien Clara Oswald Craig Owens Astrid Peth Charlotte Pollard Amy Pond Bill Potts Liz Shaw Ryan Sinclair Mickey Smith SarahJane Smith River Song Harry Sullivan Steven Taylor Nyssa Traken Rose Tyler Victoria Waterfield Rory Williams Barbara Wright