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Length of longest sub-array with maximum arithmetic mean.
• Last Updated : 27 Apr, 2021

Given an array of n-elements find the longest sub-array with the greatest arithmetic mean. The length of the sub-array must be greater than 1 and the mean should be calculated as an integer only.
Examples:

Input : arr[] = {3, 2, 1, 2}
Output : 2
sub-array 3, 2 has greatest arithmetic mean

Input :arr[] = {3, 3, 3, 2}
Output : 3

The idea is to first find the greatest mean of two consecutive elements from the array. Again iterate over the array and try to find the longest sequence in which each element must be greater or equal to the greatest mean calculated.
Above approach works because of these key points:

• Minimum possible sequence length is 2 and hence the greatest mean of two consecutive elements will always be part of the result.
• Any element which is equal or greater than the calculated mean may be the part of the longest sequence.

Below is the implementation of the above approach:

## C++

 // C++ implementation of the above approach#include using namespace std; // Function to find maximum distance// between unequal elementsint longestSubarray(int arr[], int n){     // Calculate maxMean    int maxMean = 0;    for (int i = 1; i < n; i++)        maxMean = max(maxMean,                      (arr[i] + arr[i - 1]) / 2);     // Iterate over array and calculate largest subarray    // with all elements greater or equal to maxMean    int ans = 0;    int subarrayLength = 0;    for (int i = 0; i < n; i++)        if (arr[i] >= maxMean)            ans = max(ans, ++subarrayLength);        else            subarrayLength = 0;     return ans;} // Driver codeint main(){    int arr[] = { 4, 3, 3, 2, 1, 4 };     int n = sizeof(arr) / sizeof(arr[0]);     cout << longestSubarray(arr, n);     return 0;}

## Java

 // Java implementation of the above approachimport java.io.*; class GFG{     // Function to find maximum distance// between unequal elementsstatic int longestSubarray(int arr[], int n){     // Calculate maxMean    int maxMean = 0;    for (int i = 1; i < n; i++)        maxMean = Math.max(maxMean,                    (arr[i] + arr[i - 1]) / 2);     // Iterate over array and calculate largest subarray    // with all elements greater or equal to maxMean    int ans = 0;    int subarrayLength = 0;    for (int i = 0; i < n; i++)        if (arr[i] >= maxMean)            ans = Math.max(ans, ++subarrayLength);        else            subarrayLength = 0;     return ans;} // Driver codepublic static void main (String[] args){     int arr[] = { 4, 3, 3, 2, 1, 4 };    int n = arr.length;    System.out.println (longestSubarray(arr, n));}} // This code is contributed by ajit_00023

## Python3

 # Python implementation of the above approach # Function to find maximum distance# between unequal elementsdef longestSubarray(arr, n):     # Calculate maxMean    maxMean = 0;    for i in range(1, n):        maxMean = max(maxMean,                    (arr[i] + arr[i - 1]) // 2);     # Iterate over array and calculate largest subarray    # with all elements greater or equal to maxMean    ans = 0;    subarrayLength = 0;    for i in range(n):        if (arr[i] >= maxMean):            subarrayLength += 1;            ans = max(ans, subarrayLength);        else:            subarrayLength = 0;     return ans; # Driver codearr = [ 4, 3, 3, 2, 1, 4 ]; n = len(arr); print(longestSubarray(arr, n)); # This code contributed by PrinciRaj1992

## C#

 // C# program for the above approachusing System; class GFG{         // Function to find maximum distance    // between unequal elements    static int longestSubarray(int []arr,                               int n)    {             // Calculate maxMean        int maxMean = 0;        for (int i = 1; i < n; i++)            maxMean = Math.Max(maxMean,                              (arr[i] + arr[i - 1]) / 2);             // Iterate over array and calculate        // largest subarray with all elements        // greater or equal to maxMean        int ans = 0;        int subarrayLength = 0;        for (int i = 0; i < n; i++)            if (arr[i] >= maxMean)                ans = Math.Max(ans, ++subarrayLength);            else                subarrayLength = 0;             return ans;    }         // Driver code    public static void Main ()    {             int []arr = { 4, 3, 3, 2, 1, 4 };        int n = arr.Length;        Console.WriteLine(longestSubarray(arr, n));    }} // This code is contributed by AnkitRai01

## Javascript


Output:

3

Time Complexity : O(N)

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