/*
   testarr09.cpp
   CIS 150
   06/19/2008
   David Klick

   This program shows how some of the common array tasks can
   be performed using functions.
*/

#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <ctime>
using std::cin;
using std::cout;
using std::setw;

void cont();
void initialize(int a[], int length);
void display(int a[], int length);
int sum(int a[], int length);
double average(int a[], int length);
int min(int a[], int length);
int max(int a[], int length);

int main() {
   const int ARRAY_SIZE = 10;
   int nums[ARRAY_SIZE];

   // seed the random number generator
   srand(time(0));
   
   // initialize the array to random numbers
   initialize(nums, ARRAY_SIZE);
   
   // display the array on one line
   display(nums, ARRAY_SIZE);
      
   // add up all the array elements
   cout << "The sum is " << sum(nums, ARRAY_SIZE) << '\n';

   // calculate and display the average
   cout << "The average is " << average(nums, ARRAY_SIZE) << '\n';
   
   // find the minimum value
   cout << "The smallest value is " << min(nums, ARRAY_SIZE) << '\n';
   
   // find the maximum value
   cout << "The largest value is " << max(nums, ARRAY_SIZE) << '\n';
   
   cont();
   return 0;
}

/*
   void initialize(int a[], int length);
   
   Arguments:
      int a[]: an array of integers
      int length: the number of elements in the a[] array
   
   Returns: nothing
   
   This function initializes all of the elements of the a[]
      array to random integer values between 1 and 100 inclusive.
*/
void initialize(int a[], int length) {
   for (int i=0; i<length; i++) {
      // choose a number between 1 and 100
      a[i] = rand() % 100 + 1;
   }
}

/*
   void display(int a[], int length);
   
   Arguments:
      int a[]: an array of integers
      int length: the number of elements in the a[] array
   
   Returns: nothing
   
   This function displays all of the elements of the a[]
      array with spaces inserted between them.
*/
void display(int a[], int length) {
   cout << "The array contains: ";
   for (int i=0; i<length; i++) {
      cout << a[i] << " ";
   }
   cout << '\n';
}

/*
   int sum(int a[], int length);
   
   Arguments:
      int a[]: an array of integers
      int length: the number of elements in the a[] array
   
   Returns: the sum of all of the elements in a[]
   
   This function calculates and returns the sum of
      all of the elements of the a[] array.
*/
int sum(int a[], int length) {
   int tot = 0;
   for (int i=0; i<length; i++) {
      tot += a[i];
   }
   return tot;
}

/*
   double avg(int a[], int length);
   
   Arguments:
      int a[]: an array of integers
      int length: the number of elements in the a[] array
   
   Returns: the average of all of the elements in a[]
   
   This function calculates and returns the avaerage value of
      all of the elements of the a[] array.
*/
double average(int a[], int length) {
   return sum(a, length) / (double) length;
}

/*
   int min(int a[], int length);
   
   Arguments:
      int a[]: an array of integers
      int length: the number of elements in the a[] array
   
   Returns: the minimum integer value contained in a[]
   
   This function finds and returns the smallest value found
      in the array passed to it.
*/
int min(int a[], int length) {
   int minval = a[0]; // assume the first element is the smallest
   for (int i=1; i<length; i++) {
      // now find any that are smaller
      if (a[i] < minval) minval = a[i];
   }
   return minval;
}

/*
   int max(int a[], int length);
   
   Arguments:
      int a[]: an array of integers
      int length: the number of elements in the a[] array
   
   Returns: the maximum integer value contained in a[]
   
   This function finds and returns the largest value found in
      the array passed to it.
*/
int max(int a[], int length) {
   int maxval = a[0]; // assume the first element is the smallest
   for (int i=1; i<length; i++) {
      // now find any that are smaller
      if (a[i] > maxval) maxval = a[i];
   }
   return maxval;
}

/*
   void cont();
   
   Arguments: none
   
   Returns: nothing
   
   Clears input buffer and pauses waiting for user 
   to press Enter.
*/
void cont() {
   if (cin.rdbuf()->sungetc() != -1 && cin.get() != '\n') cin.ignore(80,'\n');
   cout << "Press enter to continue...";
   cin.get();
}

/*
   Sample output:
          
   The array contains: 49 52 14 37 1 99 49 70 66 4
   The sum is 441
   The average is 44.1
   The smallest value is 1
   The largest value is 99
*/