Question

Write a program that will take input from a file of numbers of type double and output the average of the numbers in the file to the screen.

Output the file name and average.

Allow the user to process multiple files in one run.

Part A

use an array to hold the values read from the file

modify your average function so that it receives an array as input parameter, averages values in an array and returns the average

Part B

it sorts the array (Use the textbook function sort() , but you will need to change it to work with type double)

it prints the sorted array values in the output function along with the file name and the average

Use the following test data to test your program (You created files for assignment five and can reuse those):

File name	Values
class1.txt	95.6 78.3 88.8 46.7 98.5 67.1 84.0 70.3 82.4 73.6
class2.txt	95.6 78.3 88.8 46.7 98.5 67.1 84.0
class3.txt	95.6 78.3 88.8 46.7 98.5
class4.txt	70.0 80.0 90.0

Turn in copies of your program and the output from test run.

Answer 1

#include <stdio.h>
#include <stdlib.h>
double average(double *array,int size){ // function to calculate average
double sum=0;
int i=0;
for(i=0;i<size;i++)
     sum+=array[i];
return sum/size;
}
void sort(double *array,int size) // i am using bubble sort , you can use of your choice
{
     int i,j;
     double temp;
     for(i=0;i<size-1;i++){
          for(j=0;j<size-i-1;j++){
               if(array[j]>array[j+1]){
                    temp=array[j+1];
                    array[j+1]=array[j];
                    array[j]=temp;
               }
    }
     }
}
int main()
{
     FILE *fptr; // file pointer
     char file[100];
     double num[1000],number; // num is an array to store numbers from file
      int cnt=0,i,j; // cnt denotes number of elements read from file
      for(j=1;j<5;j++){
           printf("Enter file name : "); // prompting user to input file name
           scanf("%s",&file);
           fptr=fopen(file,"r"); // opening file in read mode
                if(fptr==NULL) // checking if file is correctly opened
               {
                    printf("File does not exist.");
                    continue;
               }
          while(fscanf(fptr,"%lf",&number)!=EOF) // reading from file and storing in the array until end of file is reached
         {
               num[cnt++]=number;
          }
          sort(num,cnt); // sorting the elements
          printf("File %s \nSorted order ",file);
          for(i=0;i<cnt;i++)
               printf("%.2f ",num[i]); // printing sorted elements
          printf("\nAverage %.2f\n\n",average(num,cnt)); // printing average
          fclose(fptr);
          cnt=0;
     }
     return 0;
}

Enter file name class1.txt File class1.txt Sorted order 46.70 67.10 70.30 73.60 78.30 82.40 84.00 88.80 95.60 98.50 Average 78.53 Enter file name class2.txt File class2.txt Sorted order 46.70 67.10 78.30 84.00 88.80 95.60 98.50 Average 79.86 Enter file name class3.txt File class3.txt Sorted order 46.70 78.30 88.80 95.60 98.50 Average 81.58 Enter file name class4.txt File class4.txt Sorted order 70.00 80.00 90.00 Average 80.00