Question

Write a C++ program that reads data from a file, stores data in a one-dimensional array, and processes data as required.

1) Create a text file named “hw2data.txt” that contains student test scores in the range of 0~100. You can use the following sample data: 76.5 84 75 62 94.5 75.7 93 54 36.5 87.3 81.5 89.5 68 90 79.5 80 92.5 84 96 100 67.7 78 84.5 47 100 87.5 76.25 87 82.5 64

2) Read test scores from the file “hw2data.txt” and store them in a one-dimensional array. Your program should be able to read a flexible number of scores, assuming the total number of scores is no more than 200.

3) Write a function printList that prints the content of an array on the screen. The function has two formal parameters: a double array and an int variable containing the size of the array.

4) Write a function getLargest that finds and returns the largest value (first occurrence if more than one) in an array.

5) Write a function getSmallest that finds and returns the smallest value (first occurrence if more than one) in an array.

6) Write a function getAverage that finds and returns the average value of an array.

7) Write a function getCount that finds and returns the number of times the values of an array fall in a range. This function has four formal parameters: a double array, an int variable containing the size of the array, an int variable for the lower bound of a range, and an int variable for the upper bound of the range.

8) In the function main, call the above functions to output: - all the test scores read from the file - the number of scores read from the file - the highest test score - the lowest test score - the average test score (show 2 decimal places).

9) In the function main, call the getCount function to find the number of scores in each of the following ranges: (1) 0 - 60 (0 <= score < 60, including lower bound but excluding upper bound) (2) 60 - 70 (60<= score < 70) (3) 70 – 80 (70<= score < 80) (4) 80 – 90 (80<= score < 90) (5) 90-100 (90 <= score <=100. Please note that 100 is included in this range) Output the score ranges and the number of scores in each range.

If you run your program with the above sample data, you should have results same as follows:

Range Number of Scores

0 -- 60 3

60 -- 70 4

70 -- 80 6

80 -- 90 10

90 -- 100 7

A different data file will be used to test and grade your program.

Answer 1

C++ Code :

#include<iostream>
#include <fstream>           // Input/output stream class to operate on files
using namespace std;

void printList(double arr[],int size)           // printList function() , it will print the content of the array
{
   cout<<"\nContent of the array : ";
   for(int i=0;i<size;i++)          
   cout<<arr[i]<<" ";               // printing the content of the array
}

double getSmallest(double arr[],int size)               // This function will return the smallest value in the array
{
   double min = 99999.0;           // initially, assinging a maximum value for finding the smallest value in the array
  
   for(int i=0;i<size;i++)          
   {
       if(arr[i]<min)           // finding smallest value
       min = arr[i];
   }
  
   return min;               // returning the smallest value in the array
}

double getLargest(double arr[],int size)               // This function will return the largest value in the array
{
   double max = -999.0;           // initially, assinging a minimum value for finding the smallest value in the array
  
   for(int i=0;i<size;i++)
   {
       if(arr[i]>max)           // finding largest value
       max = arr[i];
   }
  
   return max;               // returning the largest value in the array
}

int getCount(double arr[],int size,int lowerbound,int upperbound)           // this function will return the number of times the values of an array fall in a range
{
   int count = 0;               // for counting the number of times
   for(int i=0;i<size;i++)
   {
       if(upperbound!=100)               // this is the case when upperbound is not equals to 100
       {
           if(lowerbound<=arr[i] && arr[i]<upperbound)               // if upperbound is not equal to 100, we'll exclude the upperbound
           count++;               // incrementing the count by 1 if we found a match
       }
       else               // this is for special case when upperbound is equals to 100
       {
          
           if(lowerbound<=arr[i] && arr[i]<=upperbound)       // if upperbound is equal to 100, we'll include the upperbound
           count++;               // incrementing the count by 1 if we found a match
       }
   }
   return count;                       // Returning the number of times the values of an array fall in a range
}

double getAverage(double arr[],int size)               // this function will return the average of the array values
{
   double sum = 0.0;               // initially the sum is 0.0
   for(int i=0;i<size;i++)
   sum += arr[i];               // adding all the array values for finding the average
  
   double average = sum/(size*1.0);               // calculating average of the array values
   return average;                       // returning the average of the array values
}

int main()
{
   double n;               // this variable will store the array values one by one
   int size = 0;           // for counting the number of elements in the hw2data.txt
   int index = 0;               // this variable will store the index value of the array
   double ar[200];               // declaring the array of size 200 , because assuming the total number of scores is no more than 200
   ifstream read("hw2data.txt");           // reading the hw2data.txt file
   while(read>>n)           // till the input ( score ) is present in the file
   {
       ar[index] = n;               // storing the scores in the array
       size++;               // counting scores in the file
       index++;               // incrementing the index of the array after storing the score in the array
   }
  
   printList(ar,size);           // calling printList function for printing the content of the array
  
   cout<<"\n\n";
  
   double largest_value = getLargest(ar,size);               // calling getLargest() for getting the largest value in the array
   cout<<"Largest Value = "<<largest_value<<"\n\n";               // printing the largest value in the array
  
   double smallest_value = getSmallest(ar,size);               // calling getSmallest() for getting the smallest value in the array
   cout<<"Smallest Value = "<<smallest_value<<"\n\n";               // printing the smallest value in the array
  
   double average = getAverage(ar,size);               // calling getAverage() for getting the average of the array
   cout<<"Average Value = "<<average<<"\n\n";               // printing the average value of the array
      
   double count1 = getCount(ar,size,0,60);           // calling getCount for the range 0-60
   cout<<"0 -- 60 : "<<count1<<"\n\n";               // printing the count for the range 0-60
  
   double count2 = getCount(ar,size,60,70);           // calling getCount for the range 60-70
   cout<<"60 -- 70 : "<<count2<<"\n\n";               // printing the count for the range 60-70
  
   double count3 = getCount(ar,size,70,80);           // calling getCount for the range 70-80
   cout<<"70 -- 80 : "<<count3<<"\n\n";               // printing the count for the range 70-80
  
   double count4 = getCount(ar,size,80,90);           // calling getCount for the range 80-90
   cout<<"80 -- 90 : "<<count4<<"\n\n";               // printing the count for the range 80-90
  
   double count5 = getCount(ar,size,90,100);           // calling getCount for the range 90-100
   cout<<"90 -- 100 : "<<count5<<"\n\n";               // printing the count for the range 90-100  
}

Output :