Given an array, the task is to find average of that array. Average is the sum of array elements divided by the number of elements.
Examples :
Input : arr[] = {1, 2, 3, 4, 5}
Output : 3
Sum of the elements is 1+2+3+4+5 = 15
and total number of elements is 5.
So average is 15/5 = 3
Input : arr[] = {5, 3, 6, 7, 5, 3}
Output : 4.83333
Sum of the elements is 5+3+6+7+5+3 = 29
and total number of elements is 6.
So average is 29/6 = 4.83333.
Iterative:
Iterative program is easy. We need to find sum and divide sum by total number of elements.
C++
#include <iostream>
using namespace std;
double average(int a[], int n)
{
int sum = 0;
for (int i=0; i<n; i++)
sum += a[i];
return (double)sum/n;
}
int main()
{
int arr[] = {10, 2, 3, 4, 5, 6, 7, 8, 9};
int n = sizeof(arr)/sizeof(arr[0]);
cout << average(arr, n) << endl;
return 0;
}
|
Java
class GFG {
static double average(int a[], int n)
{
int sum = 0;
for (int i = 0; i < n; i++)
sum += a[i];
return (double)sum / n;
}
public static void main (String[] args)
{
int arr[] = {10, 2, 3, 4, 5, 6, 7, 8, 9};
int n = arr.length;
System.out.println(average(arr, n));
}
}
|
Python3
def average( a , n ):
sum = 0
for i in range(n):
sum += a[i]
return sum/n;
arr = [10, 2, 3, 4, 5, 6, 7, 8, 9]
n = len(arr)
print(average(arr, n))
|
C#
using System;
class GFG {
static double average(int []a, int n)
{
int sum = 0;
for (int i = 0; i < n; i++)
sum += a[i];
return (double)sum / n;
}
public static void Main ()
{
int []arr = {10, 2, 3, 4, 5, 6,
7, 8, 9};
int n = arr.Length;
Console.Write(average(arr, n));
}
}
|
PHP
<?php
function average( $a, $n)
{
$sum = 0;
for ( $i = 0; $i < $n; $i++)
$sum += $a[$i];
return $sum / $n;
}
$arr = array(10, 2, 3, 4, 5,
6, 7, 8, 9);
$n = count($arr);
echo average($arr, $n);
?>
|
Recursive:
The idea is to pass index of element as an additional parameter and recursively compute sum. After computing sum, divide the sum by n.
C++
#include <iostream>
using namespace std;
double avgRec(int a[], int i, int n)
{
if (i == n-1)
return a[i];
if (i == 0)
return ((a[i] + avgRec(a, i+1, n))/n);
return (a[i] + avgRec(a, i+1, n));
}
double average(int a[], int n)
{
return avgRec(a, 0, n);
}
int main()
{
int arr[] = {10, 2, 3, 4, 5, 6, 7, 8, 9};
int n = sizeof(arr)/sizeof(arr[0]);
cout << average(arr, n) << endl;
return 0;
}
|
Java
class CalcAvg
{
static double avgRec(int a[], int i, int n)
{
if (i == n-1)
return a[i];
if (i == 0)
return ((a[i] + avgRec(a, i+1, n))/n);
return (a[i] + avgRec(a, i+1, n));
}
static double average(int a[], int n)
{
return avgRec(a, 0, n);
}
public static void main (String[] args)
{
int arr[] = {10, 2, 3, 4, 5, 6, 7, 8, 9};
int n = arr.length;
System.out.println(average(arr, n));
}
}
|
Python3
def avgRec( a , i , n ):
if i == n-1:
return a[i]
if i == 0:
return ((a[i] + avgRec(a, i+1, n)) / n)
return (a[i] + avgRec(a, i+1, n))
def average(a, n):
return avgRec(a, 0, n)
arr = [10, 2, 3, 4, 5, 6, 7, 8, 9]
n = len(arr)
print(average(arr, n))
|
C#
using System;
class GFG {
static double avgRec(int []a, int i, int n)
{
if (i == n-1)
return a[i];
if (i == 0)
return ((a[i] + avgRec(a, i+1, n))/n);
return (a[i] + avgRec(a, i+1, n));
}
static double average(int []a, int n)
{
return avgRec(a, 0, n);
}
public static void Main ()
{
int []arr = {10, 2, 3, 4, 5, 6, 7, 8, 9};
int n = arr.Length;
Console.Write(average(arr, n));
}
}
|
PHP
<?php
function avgRec($a, $i, $n)
{
if ($i == $n - 1)
return $a[$i];
if ($i == 0)
return (($a[$i] +
avgRec($a, $i +
1, $n)) / $n);
return ($a[$i] +
avgRec($a, $i + 1, $n));
}
function average($a, $n)
{
return avgRec($a, 0, $n);
}
$arr = array(10, 2, 3, 4,
5, 6, 7, 8, 9);
$n = sizeof($arr);
echo average($arr, $n) ;
?>
|
Related Article :
Average of a stream of numbers
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