Question

C++ coding, help
In this program you will be reading numbers from a file. You will validate the numbers and calculate the average of all of the valid numbers.
Your program will read in a file with numbers. The numbers will be of type double.
The numbers should be in the range from 0 to 110 (inclusive). You need to count all of the numbers between 0 and 110. You also need to calculate the average of these numbers.
If a number is not valid (that is, it is less than 0 or greater than 110) you need to count it (as a count of invalid values) and you need to write out the number to a file called "invalid-numbers.txt". Values written to file invalid-numbers.txt should be in fixed format with two digits to the right of the decimal point.
As you did in lab lesson 7 part 1 you need to read in the input file name using cin.
The output from your program will be written to cout. The output must contain the file being processed, the total number of values read in from the file, the number of invalid values read in, the number of valid values read in.
The last thing you need to output is either the average of the valid values or an error message. The average must have two digits of precision to the right of the decimal point and must be in fixed format. If there is not valid average you should output the message:
An average cannot be calculated
In what case would you display this message?
If the input file cannot be opened, you will need to output a message. Assume the input file name is badinput.txt and it cannot be opened. You will display the following error message to cout
File "badinput.txt" could not be opened
Here is an example of a working program:
Assume the file name read in from cin is:
input.txt
and that input.txt contains:
-12
0
98.5
100
105.5
93.5
88
75
-3
111
89
-12
Your program would output the following:
Reading from file "input.txt"
Total values: 12
Invalid values: 4
Valid values: 8
Average of valid values: 81.19
The contents written out to file invalid-numbers.txt are:
-12
-3
111
-12
You are reading from an input file and you are writing to an output file. Make sure you close both files after you are finished using them. You must do this in your program, you cannot just let the operating system close the files for you.
For tests where there is output written to an output file the contents of the output file will determine if you passed that test or not. For cases where you have written out to cout the tests will check the output sent to cout. In some cases output will be written to a file and to cout. When this is the case the test will be run twice with the same input. Once to test cout and once to test the contents of the output file. An example of this would be tests 2 and 3. Both use the same input file. Test 2 check the output written to cout and test 3 checks the output written to the file invalid-numbers.txt.

Answer 1

Answer:

The program in C++ is as follows:

#include <fstream>

#include <iostream>

#include <iomanip>

using namespace std;

int main() {

 string filename;

 cout<<"Filename: ";

 cin>>filename;

 ifstream inFile(filename);

 if(!inFile) {

   cout << endl << "Cannot open file " << filename;

   return 1;  }  

 ofstream fout;

 ifstream fin;

 fin.open("invalid-numbers.txt");  

 fout.open ("invalid-numbers.txt",ios::app);  

 double sum = 0; int valid = 0; int invalid = 0;

 double num = 0;

 while(!inFile.eof()) {

   inFile >> num;

   if(num >= 0 && num<=110){   sum+=num; valid++; }

else{ invalid++;

if(fin.is_open()){

   fout<<fixed<<setprecision(2)<<num<<"\n";    }  }  }

 fin.close();

 fout.close();

 inFile.close();

 cout<<"Total values: "<<valid+invalid<<endl;

 cout<<"Invalid values: "<<invalid<<endl;

 cout<<"Valid values: "<<valid<<endl;

 cout<<"Average of valid values: "<<fixed<<setprecision(2)<<sum/valid<<endl;    

 double inv;

 ifstream inFiles("invalid-numbers.txt");

 while(!inFiles.eof()) {

   inFiles >> inv;

   cout<<inv<<"\n";

}

inFiles.close();

 return 0;

}

Explanation:

See attachment for source file where comments are used to explain each line