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#include <iostream>
#include <fstream> // I/O
#include <iomanip> // For setw()
using namespace std;
ofstream outputfile("output.txt");
const int MAX_FILE_NAME = 35; // Maximum file name length
const int MAX_NUMBER_SCORES = 40; // Maximum number of values in array
void open_input(ifstream& input, char name[]); // Get file name, Open file
void read_values(ifstream& input, double v[], int size, int& used); // Read values from file
void find_max_min(const double v[], int n, double& max, double& min);// Find max/min in array
double find_average(ifstream& input);
void output(const char name[], const double v[], int n,
double average, ostream &out = cout); // Print Results
void sort(double a[], int number_used);
//Precondition: number_used <= declared size of the array a.
//The array elements a[0] through a[number_used - 1] have values.
//Postcondition: The values of a[0] through a[number_used - 1] have
//been rearranged so that a[0] <= a[1] <= ... <= a[number_used - 1].
void swap_values(double& v1, double& v2);
//Interchanges the values of v1 and v2.
int index_of_smallest(const double a[], int start_index, int number_used);
//Precondition: 0 <= start_index < number_used.
//Referenced array elements have values.
//Returns the index i such that a[i] is the smallest of the values
//a[start_index], a[star_index + 1], ..., a[number_used - 1].
int main()
// Parameters: None
// Returns: Zero
// Calls: open_input(), read_values(), find_max_min(), output()
{ char again; // Does user want to go through loop again?
char file_name[MAX_FILE_NAME + 1]; // Name of file to be processed
ifstream input_numbers; // Input file of doubles
double scores[MAX_NUMBER_SCORES]; // Array to hold scores processed
//double max, min; // Maximum and minimum numbers from file
double average;
int num_scores; // Number of scores in file
cout << "This program can find the average number in a file\n"
<< "of at most " << MAX_NUMBER_SCORES << " floating-point values.\n" << endl;
system("pause"); // Hold message on screen until key is pressed
do
{ open_input(input_numbers, file_name); // Get file name & open file
read_values(input_numbers, scores,
MAX_NUMBER_SCORES, num_scores); // Read values
input_numbers.close(); // Close file
if (num_scores > 0)
{ find_average(scores, num_scores, average); // Find max & min values in array
sort(scores, num_scores);
output(file_name, scores, num_scores, average); //Print results on screen
output(file_name, scores, num_scores, average, outputfile); // and outputfile
}
else
{ cout << "\n\n\aNo data in file: " << file_name << endl;
}
cout << "\nDo you want to process another file (Y/N)? ";
cin >> again;
cin.ignore(256, '\n'); // Remove Enter key from keyboard buffer
} while ( again == 'y' || again == 'Y');
cout << "\nEnd of Program!" << endl;
outputfile << "\n\nThanks for using MaxMin!\f";
outputfile.close();
return 0;
} // End of main()
void open_input(ifstream& input, char name[]) //Open file
// Parameters: Variables for input file reference nad input file name
// Returns: None
// Calls: None
{ int count = 0; // Count number of tries
do // Continue until we get a valid file name and can open file
{ count++;
if (count != 1) // Issue error message if we are trying again.
{ cout << "\n\aInvalid file name or file does not exist. Please try again."
<< endl;
}
cout << "\nEnter the input file name (maximum of " << MAX_FILE_NAME
<< " characters please)\n:> ";
cin.get(name, MAX_FILE_NAME + 1);// Gets at most MAX_FILE_NAME characters
cin.ignore(256, '\n'); // Remove Enter key from keyboard buffer
input.clear(); // Clear all error flags, if any, from prev try
input.open(name, ios_base::in); // Open to read only if file exists
} while (input.fail() ); // If can't open file, try again
} // End of open_input()
void read_values(ifstream& input, double v[], int size, int& used) // Read values
// Parameters: Variables for file reference, variable for array reference,
// value for array size and variable for number of values in array
// Returns: None
// Calls: None
{
double value; // Value from file
int count = 0; // Count number of values in file
while (count < size && input >> value) // Continue as long as there is
// room in the array and we can read
{ v[count] = value; // a number from file.
count ++;
}
used = count;
} // End of read_values()
void find_max_min(const double v[], int n, double& max, double& min) // Find max & min values
// Parameters: Variables for array reference, value for number of values
// and variables for max and min values
// Returns: None
// Calls: None
{
int i; // Array index and loop counter
max = min = v[0];
for (i = 1; i < n; i++) // Start with 1 since max & min initialized to v[0]
{
if (v[i] > max) max = v[i];
if (v[i] < min) min = v[i];
}
} // End of find_max_min()
double find_average(ifstream& input)
// Parameters: Variables for file reference and max and min values
// Returns: None
// Calls: None
{
double i; // Value from file
double sum = 0;
int count = 0;
for (i = 0; i < n; i++) // Continue as long as we can read a number from file.
{
sum += v[i];
count++;
}
return sum/count;
}
void output(const char name[], const double v[], int n,
double average, ostream& out)
// Parameters: File name, array reference, number of values and max & min values
// Returns: None
// Calls: None
{ int i; // Array index and loop counter
out.setf(ios::fixed);
out.setf(ios::showpoint);
out.precision(1);
out << "\n\nInput File Name: " << name << endl;
out << "\nFile Contents:" << endl;
for (i = 0; i < n; )
{ out << setw(8) << v[i];
if ( ++i % 5 == 0) out << "\n"; // Print only 5 values per line
}
if ( i % 5 != 0) out << "\n"; // Newline if last line is short
out << "\nAverage Number in File: " << setw(8) << average << endl;
} // End of output()
void sort(double a[], int number_used)
{
int index_of_next_smallest;
for (int index = 0; index < number_used - 1; index++)
{//Place the correct value in a[index]:
index_of_next_smallest =
index_of_smallest(a, index, number_used);
swap_values(a[index], a[index_of_next_smallest]);
//a[0] <= a[1] <=...<= a[index] are the smallest of the original array
//elements. The rest of the elements are in the remaining positions.
}
}
void swap_values(double& v1, double& v2)
{
double temp;
temp = v1;
v1 = v2;
v2 = temp;
}
int index_of_smallest(const double a[], int start_index, int number_used)
{
double min = a[start_index];
int index_of_min = start_index;
for (int index = start_index + 1; index < number_used; index++)
if (a[index] < min)
{
min = a[index];
index_of_min = index;
//min is the smallest of a[start_index] through a[index]
}
return index_of_min;
}
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