# Program for Mean and median of an unsorted array

Given n size unsorted array, find its mean and median.

```Mean of an array = (sum of all elements) /
(number of elements)

Median of a sorted array of size n is defined
as below :
It is middle element when n is odd and average
of middle two elements when n is even.

Since the array is not sorted here, we sort
the array first, then apply above formula.
```

Examples:

```Input  : a[] = {1, 3, 4, 2, 6, 5, 8, 7}
Output : Mean = 4.5
Median = 4.5
Sum of the elements is 1 + 3 + 4 + 2 + 6 +
5 + 8 + 7 = 36
Mean = 36/8 = 4.5
Since number of elements are even, median
is average of 4th and 5th largest elements.
which means (4 + 5)/2 = 4.5

Input  : a[] = {4, 4, 4, 4, 4}
Output : Mean = 4
Median = 4
```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Below is the code implementation:

## C++

 `// CPP program to find mean and median of  ` `// an array ` `#include ` `using` `namespace` `std; ` ` `  `// Function for calculating mean ` `double` `findMean(``int` `a[], ``int` `n) ` `{ ` `    ``int` `sum = 0; ` `    ``for` `(``int` `i = 0; i < n; i++)  ` `        ``sum += a[i]; ` `     `  `    ``return` `(``double``)sum/(``double``)n; ` `} ` ` `  `// Function for calculating median ` `double` `findMedian(``int` `a[], ``int` `n) ` `{ ` `    ``// First we sort the array ` `    ``sort(a, a+n); ` ` `  `    ``// check for even case ` `    ``if` `(n % 2 != 0) ` `       ``return` `(``double``)a[n/2]; ` `     `  `    ``return` `(``double``)(a[(n-1)/2] + a[n/2])/2.0; ` `} ` ` `  `// Driver program ` `int` `main() ` `{ ` `    ``int` `a[] = { 1, 3, 4, 2, 7, 5, 8, 6 }; ` `    ``int` `n = ``sizeof``(a)/``sizeof``(a[0]); ` `    ``cout << ``"Mean = "` `<< findMean(a, n) << endl;  ` `    ``cout << ``"Median = "` `<< findMedian(a, n) << endl;  ` `    ``return` `0; ` `} `

## Java

 `// Java program to find mean  ` `// and median of an array ` `import` `java.util.*; ` ` `  `class` `GFG ` `{ ` `    ``// Function for calculating mean ` `    ``public` `static` `double` `findMean(``int` `a[], ``int` `n) ` `    ``{ ` `        ``int` `sum = ``0``; ` `        ``for` `(``int` `i = ``0``; i < n; i++)  ` `            ``sum += a[i]; ` `     `  `        ``return` `(``double``)sum / (``double``)n; ` `    ``} ` ` `  `    ``// Function for calculating median ` `    ``public` `static` `double` `findMedian(``int` `a[], ``int` `n) ` `    ``{ ` `        ``// First we sort the array ` `        ``Arrays.sort(a); ` ` `  `        ``// check for even case ` `        ``if` `(n % ``2` `!= ``0``) ` `        ``return` `(``double``)a[n / ``2``]; ` `     `  `        ``return` `(``double``)(a[(n - ``1``) / ``2``] + a[n / ``2``]) / ``2.0``; ` `    ``} ` ` `  `    ``// Driver program ` `    ``public` `static` `void` `main(String args[]) ` `    ``{ ` `        ``int` `a[] = { ``1``, ``3``, ``4``, ``2``, ``7``, ``5``, ``8``, ``6` `}; ` `        ``int` `n = a.length; ` `        ``System.out.println(``"Mean = "` `+ findMean(a, n));  ` `        ``System.out.println(``"Median = "` `+ findMedian(a, n));  ` `    ``} ` `} ` ` `  `// This article is contributed by Anshika Goyal. `

## Python3

 `# Python3 program to find mean  ` `# and median of an array ` ` `  `# Function for calculating mean ` `def` `findMean(a, n): ` ` `  `    ``sum` `=` `0` `    ``for` `i ``in` `range``( ``0``, n): ` `        ``sum` `+``=` `a[i] ` `     `  `    ``return` `float``(``sum``/``n) ` ` `  `# Function for calculating median ` `def` `findMedian(a, n): ` ` `  `    ``# First we sort the array ` `    ``sorted``(a) ` ` `  `    ``# check for even case ` `    ``if` `n ``%` `2` `!``=` `0``: ` `        ``return` `float``(a[n``/``2``]) ` `     `  `    ``return` `float``((a[``int``((n``-``1``)``/``2``)] ``+` `                  ``a[``int``(n``/``2``)])``/``2.0``) ` ` `  `# Driver program ` `a ``=` `[ ``1``, ``3``, ``4``, ``2``, ``7``, ``5``, ``8``, ``6` `] ` `n ``=` `len``(a) ` `print``(``"Mean ="``, findMean(a, n)) ` `print``(``"Median ="``, findMedian(a, n)) ` ` `  `# This code is contributed by Smitha Dinesh Semwal `

## C#

 `// C# program to find mean  ` `// and median of an array ` `using` `System; ` ` `  `class` `GFG ` `{ ` `    ``// Function for  ` `    ``// calculating mean ` `    ``public` `static` `double` `findMean(``int` `[]a,  ` `                                  ``int` `n) ` `    ``{ ` `        ``int` `sum = 0; ` `        ``for` `(``int` `i = 0; i < n; i++)  ` `            ``sum += a[i]; ` `     `  `        ``return` `(``double``)sum /  ` `               ``(``double``)n; ` `    ``} ` ` `  `    ``// Function for  ` `    ``// calculating median ` `    ``public` `static` `double` `findMedian(``int` `[]a, ` `                                    ``int` `n) ` `    ``{ ` `        ``// First we sort ` `        ``// the array ` `        ``Array.Sort(a); ` ` `  `        ``// check for  ` `        ``// even case ` `        ``if` `(n % 2 != 0) ` `        ``return` `(``double``)a[n / 2]; ` `     `  `        ``return` `(``double``)(a[(n - 1) / 2] +  ` `                        ``a[n / 2]) / 2.0; ` `    ``} ` ` `  `    ``// Driver Code ` `    ``public` `static` `void` `Main() ` `    ``{ ` `        ``int` `[]a = {1, 3, 4, 2,  ` `                   ``7, 5, 8, 6}; ` `        ``int` `n = a.Length; ` `        ``Console.Write(``"Mean = "` `+  ` `                       ``findMean(a, n) +  ` `                                 ``"\n"``);  ` `        ``Console.Write(``"Median = "` `+  ` `                       ``findMedian(a, n) +  ` `                                   ``"\n"``);  ` `    ``} ` `} ` ` `  `// This code is contributed by Smitha . `

## PHP

 ` `

Output:

```Mean = 4.5
Median = 4.5
```

Time Complexity to find mean = O(n)
Time Complexity to find median = O(n Log n) as we need to sort the array first. Note that we can find median in O(n) time using methods discussed here and here.

This article is contributed by Himanshu Ranjan. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

My Personal Notes arrow_drop_up

Article Tags :
Practice Tags :

Be the First to upvote.

Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.