// Dackral Phillips
// Comp 6700 - The Software Process

// This program calculates the mean and the standard deviation of a group of numbers
// stored in a linked list.

#include <iostream.h>
#include <iomanip.h>
#include <math.h>

// Make nodes in which to store numbers

   class Node
   {
   public:
   
      Node() 
      {
         init();
      }
   
      Node(int Value) 
      {
         init(Value);
      }
   
      void init() 
      {
         value = 0;
         next = NULL;
      }
   
      void init(int Value) 
      {
         value = Value;
         next = NULL;
      }
   
      Node* Next() 
      {
         return next;
      }
   
      void setNext(Node *nextPtr)
      {
         next = nextPtr;
      }
   
      double GetValue();
   
   private:
      double value;
      Node *next;
   };

   double Node::GetValue()
   {
      return value;
   }

   class LinkedList
   {
   public:
   
      LinkedList() 
      {
         init();
      }
   
      ~LinkedList();
   
      void init() 
      {
         items = 0;
         mean = 0;
         stddeviation = 0;
         first = NULL;
      }
   
      void add(int Value);
      double Mean();
      double StdDeviation();
   
   private:
      int items;
      double mean;
      double stddeviation;
      Node *first;
   };

   void LinkedList::add(int Value)
   {
      Node *temp;
   
      items++;
      temp = new Node(Value);
      temp->setNext(first);
      first = temp;
   }

   double LinkedList::Mean()
   {
      Node *temp;
      Node *trail;
   
      trail = first;
   
      while (first != NULL)
      {
         temp = first;
         first = first->Next();
         mean = mean + temp->GetValue();
      }
      mean = mean / items;
   
      first = trail;
   
      return mean;
   }

   double LinkedList::StdDeviation()
   {
      Node *temp;
      Node *trail;
      double difference;
   
      trail = first;
   
      while (first != NULL)
      {
         temp = first;
         first = first->Next();
         difference = temp->GetValue();
         difference = difference - mean;
         stddeviation = stddeviation + (difference * difference);
      }
      stddeviation = stddeviation / (items - 1);
   	stddeviation = sqrt(stddeviation);
   
      first = trail;
   
      return stddeviation;
   
   }

   LinkedList::~LinkedList()
   {
      Node *temp;
   
      while (first != NULL)
      {
         temp = first;
         first = first->Next();
         temp ->init();
         delete temp;
         temp = NULL;
      }
   }

   int main()
   {
      LinkedList testset1;
      LinkedList testset2;
      LinkedList testset3;
      double mean1, mean2, mean3;
      double stddeviation1, stddeviation2, stddeviation3;
   
      testset1.add(160);
      testset1.add(591);
      testset1.add(114);
      testset1.add(229);
      testset1.add(230);
      testset1.add(270);
      testset1.add(128);
      testset1.add(1675);
      testset1.add(624);
      testset1.add(1503);
   
      mean1 = testset1.Mean();
      stddeviation1 = testset1.StdDeviation();
   
      testset2.add(186);
      testset2.add(699);
      testset2.add(132);
      testset2.add(272);
      testset2.add(291);
      testset2.add(331);
      testset2.add(199);
      testset2.add(1890);
      testset2.add(788);
      testset2.add(1601);
   
      mean2 = testset2.Mean();
      stddeviation2 = testset2.StdDeviation();
   
      testset3.add(15.0);
      testset3.add(69.9);
      testset3.add(6.5);
      testset3.add(22.4);
      testset3.add(28.4);
      testset3.add(65.9);
      testset3.add(19.4);
      testset3.add(198.4);
      testset3.add(38.8);
      testset3.add(138.2);
   
      mean3 = testset3.Mean();
      stddeviation3 = testset3.StdDeviation();
   
      cout << "The Mean of Test Set #1 is: " << mean1 << endl
         << "The Standard Deviation of Test Set #1 is: " << stddeviation1 << endl << endl;
      cout << "The Mean of Test Set #2 is: " << mean2 << endl
         << "The Standard Deviation of Test Set #2 is: " << stddeviation2 << endl << endl;
      cout << "The Mean of Test Set #3 is: " << mean3 << endl
         << "The Standard Deviation of Test Set #3 is: " << stddeviation3 << endl << endl;
   
      return 0;
   }