Question

Write a program in C++ that reads in integer numbers from a file called scores.txt until the sentinel value -999 is read. The program should then output the total and average of the numbers read and output each of the numbers incremented by the overall average to a file called or scoresout.txt along with the sentinel value of -999 at the end

So if 10, 20, 30 and -999 are read in then the program would display a total of 60 and an average of 20 then output to the scoresout.dat file 30, 40, 50 and -999.

Hint: So read input file, compute the total and the average (put that into a variable) then close the input file. After that, re-open the input file, open the output file, take each number from the input file, add the average to it then output it to the output file.

scores.txt content

10
20
30
40
50
60
-999

scoresout.txt

45
55
65
75
85
95
-999

Please for some comments in the code explaining the process and no need for full file directories. The file name will be enough.

Answer 1

Here is code:

#include <iostream>

#include <fstream>

using namespace std;

int *expander(int ex_arr[], int counter, int value)

{

int *new_arr = (int *)malloc(sizeof(int) * (counter + 1));

int i;

for (i = 0; i < counter; i++)

{

new_arr[i] = ex_arr[i];

}

new_arr[i] = value;

return new_arr;

}

void printArray(int *array, int size)

{

fstream fout("files\\scoresout.txt", ios::out);

for (int i = 0; i < size; i++)

{

fout << array[i] << endl;

}

fout.close();

}

int main()

{

int *array;

fstream inFile("files\\scores.txt", ios_base::in);

int a;

int count = 0;

// loop the file numbers

while (inFile >> a && a != -999)

{

array = expander(array, count++, a);

}

int sum = 0;

double avg = 0;

for (int i = 0; i < count; i++)

{

sum += array[i];

}

avg = (double)sum / count;

for (int i = 0; i < count; i++)

{

array[i] += avg;

}

printArray(array, count);

inFile.close();

cout << "Done\n";

return 0;

}

Output: