Longest subarray in which all elements are greater than K

Given an array of N integers and a number K, the task is to find the length of the longest subarray in which all the elements are greater than K. 

Examples:

Input: a[] = {3, 4, 5, 6, 7, 2, 10, 11}, K = 5 
Output: 2 
There are two possible longest subarrays of length 2. 
They are {6, 7} and {10, 11}.

Input: a[] = {8, 25, 10, 19, 19, 18, 20, 11, 18}, K = 13 
Output: 4 
The longest subarray is {19, 19, 18, 20}. 

The idea is to start traversing the array using a counter. If the current element is greater than the given value X, increment the counter otherwise replace the previous length with the maximum of the previous length and current counter and reset the counter.

Below is the implementation of the above approach. 

C++

// C++ program to print the length of the longest
// subarray with all elements greater than X
#include <bits/stdc++.h>
using namespace std;

// Function to count number of segments
int longestSubarray(int a[], int n, int x)
{
    int count = 0;

    int length = 0;

    // Iterate in the array
    for (int i = 0; i < n; i++) {

        // check if array element
        // greater than X or not
        if (a[i] > x) {
            count += 1;
        }
        else {

            length = max(length, count);

            count = 0;
        }
    }

    // After iteration complete
    // check for the last segment
    if (count)
        length = max(length, count);

    return length;
}

// Driver Code
int main()
{
    int a[] = { 8, 25, 10, 19, 19, 18, 20, 11, 18 };
    int n = sizeof(a) / sizeof(a[0]);
    int k = 13;

    cout << longestSubarray(a, n, k);

    return 0;
}

Java

// Java program to print the length of the longest
// subarray with all elements greater than X

import java.io.*;

class GFG {

// Function to count number of segments
static int longestSubarray(int a[], int n, int x)
{
    int count = 0;

    int length = 0;

    // Iterate in the array
    for (int i = 0; i < n; i++) {

        // check if array element
        // greater than X or not
        if (a[i] > x) {
            count += 1;
        }
        else {

            length = Math.max(length, count);

            count = 0;
        }
    }

    // After iteration complete
    // check for the last segment
    if (count>0)
        length = Math.max(length, count);

    return length;
}

// Driver Code
    public static void main (String[] args) {
            int []a = { 8, 25, 10, 19, 19, 18, 20, 11, 18 };
    int n = a.length;
    int k = 13;

  System.out.println(longestSubarray(a, n, k));
    }
}
// This Code is contributed
// by shs

Python3

# Python3 program to print the length of
# the longest subarray with all elements
# greater than X

# Function to count number of segments
def longestSubarray(a, n, x):
    count = 0
    length = 0

    # Iterate in the array
    for i in range(n):

        # check if array element greater
        # than X or not
        if (a[i] > x):
            count += 1
        else:
            length = max(length, count)
            count = 0

    # After iteration complete
    # check for the last segment
    if (count > 0):
        length = max(length, count)
    return length

# Driver Code
if __name__ == '__main__':
    a = [ 8, 25, 10, 19, 19,
             18, 20, 11, 18 ]
    n = len(a)
    k = 13
    print(longestSubarray(a, n, k))

# This code is contributed by 29AjayKumar

C#

// C# program to print the length of the longest
// subarray with all elements greater than X

using System;

class GFG {

// Function to count number of segments
static int longestSubarray(int []a, int n, int x)
{
    int count = 0;

    int length = 0;

    // Iterate in the array
    for (int i = 0; i < n; i++) {

        // check if array element
        // greater than X or not
        if (a[i] > x) {
            count += 1;
        }
        else {

            length = Math.Max(length, count);

            count = 0;
        }
    }

    // After iteration complete
    // check for the last segment
    if (count>0)
        length = Math.Max(length, count);

    return length;
}

// Driver Code
    public static void Main () {
            int []a = { 8, 25, 10, 19, 19, 18, 20, 11, 18 };
    int n = a.Length;
    int k = 13;

Console.WriteLine(longestSubarray(a, n, k));
    }
}
// This Code is contributed
// by shs

PHP

<?php
// PHP program to print the length
// of the longest subarray with all
// elements greater than X

// Function to count number of segments
function longestSubarray($a, $n, $x)
{
    $count = 0;

    $length = 0;

    // Iterate in the array
    for ($i = 0; $i < $n; $i++)
    {

        // check if array element
        // greater than X or not
        if ($a[$i] > $x)
        {
            $count += 1;
        }
        else
        {
            $length = max($length, $count);

            $count = 0;
        }
    }

    // After iteration complete
    // check for the last segment
    if ($count > 0)
        $length = max($length, $count);

    return $length;
}

// Driver Code
$a = array( 8, 25, 10, 19, 19,
            18, 20, 11, 18 );
$n = 9;
$k = 13;

echo longestSubarray($a, $n, $k);

// This code is contributed
// by Arnab Kundu
?>

Javascript

<script>
// javascript program to print the length of the longest
// subarray with all elements greater than X
// Function to count number of segments
    function longestSubarray(a , n , x) {
        var count = 0;

        var length = 0;

        // Iterate in the array
        for (i = 0; i < n; i++) {

            // check if array element
            // greater than X or not
            if (a[i] > x) {
                count += 1;
            } else {

                length = Math.max(length, count);

                count = 0;
            }
        }

        // After iteration complete
        // check for the last segment
        if (count > 0)
            length = Math.max(length, count);

        return length;
    }

    // Driver Code

        var a = [ 8, 25, 10, 19, 19, 18, 20, 11, 18 ];
        var n = a.length;
        var k = 13;

        document.write(longestSubarray(a, n, k));

// This code is contributed by todaysgaurav
</script>

Output

4

Complexity Analysis:

• Time Complexity: O(N) 
• Auxiliary Space: O(1)