persort.cpp

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// persort.cpp
// sorts person objects using array of pointers
#include <iostream>
#include <string>                 //for string class
using namespace std;             
////////////////////////////////////////////////////////////////
class person                      //class of persons
   {
   protected:
      string name;                //person's name
   public:
      void setName()              //set the name
         { cout << "Enter name: "; cin >> name; }
      void printName()            //display the name
         { cout << endl << name; }
      string getName()            //return the name
         { return name; }
   };
////////////////////////////////////////////////////////////////
int main()
   {
   void bsort(person**, int);     //prototype
   person* persPtr[100];          //array of pointers to persons
   int n = 0;                     //number of persons in array
   char choice;                   //input char
          
   do {                           //put persons in array
      persPtr[n] = new person;    //make new object
      persPtr[n]->setName();      //set person's name
      n++;                        //count new person
      cout << "Enter another (y/n)? "; //enter another
      cin >> choice;              //   person?
      }
   while( choice=='y' );          //quit on 'n'

   cout << "\nUnsorted list:";
   for(int j=0; j<n; j++)         //print unsorted list
      { persPtr[j]->printName(); }     

   bsort(persPtr, n);             //sort pointers

   cout << "\nSorted list:";
   for(j=0; j<n; j++)             //print sorted list
      { persPtr[j]->printName(); }
   cout << endl;
   return 0;
   }  //end main()
//--------------------------------------------------------------
void bsort(person** pp, int n)    //sort pointers to persons
   {                              
   void order(person**, person**);  //prototype
   int j, k;                      //indexes to array

   for(j=0; j<n-1; j++)           //outer loop
      for(k=j+1; k<n; k++)        //inner loop starts at outer
	      order(pp+j, pp+k);       //order the pointer contents
   }
//--------------------------------------------------------------
void order(person** pp1, person** pp2)  //orders two pointers
   {                              //if 1st larger than 2nd,
   if( (*pp1)->getName() > (*pp2)->getName() )
      {
      person* tempptr = *pp1;     //swap the pointers
      *pp1 = *pp2;
      *pp2 = tempptr;
      }
   }