Maximum Average subarray of k length in C++

April 12, 2023

Maximum Average Sub-array of K length

On this page we will discuss about Maximum Average sub-array of k length in C++ language . We have to Find out the maximum possible average value of sub-array of K length from  given sequence of N integers, a[1], a[2], , , , a[N] of  N length and a integer K integer.

Average sub-array

Maximum Average Sub-array of K length in C++

In C++, maximum average subarray of k length pertains to a contiguous sub-array of length k in a given array of numbers, where the average (mean) of the k elements is the highest among all possible sub-arrays of length k in that array. In simpler words, it refers to the sub-array of k consecutive elements whose sum is the largest possible among all sub-arrays of k consecutive elements in the array, resulting in the highest average value.

For example,consider the array

[1, 12, -5, -6, 50, 3] and k=4.

The subarrays of length 4 are [1, 12, -5, -6], [12, -5, -6, 50], [-5, -6, 50, 3], and their averages are 0.5, 12.75, and 10.5 respectively. The maximum average subarray of length 4 in this case is [12, -5, -6, 50], whose average is 12.75.

Maximum Average Sub-array of K length in C++
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Algorithm:

  1. Initialize max_sum with the sum of the first k elements of arr and max_end with k-1, which represent the sum and ending index of the first subarray of length k.

  2. Loop through the input array arr from index k to n-1 and for each index i, compute the sum of the subarray of length k ending at index i, i.e., curr_sum = sum of elements from arr[i-k+1] to arr[i].

  3. Compare curr_sum with max_sum. If curr_sum is greater than max_sum, update max_sum with curr_sum and update max_end with the current index i.

  4. After the loop, max_end will represent the ending index of the maximum average subarray of length k.

  5. Return the starting index of the maximum average subarray of length k as max_end - k + 1.

C++  code for maximum average sub-array of k length

Run 
#include<bits/stdc++.h>
using namespace std;
 
// Returns beginning index of maximum average
// subarray of length 'k'
int findMaxAverage(int arr[], int n, int k)
{
    // Check if 'k' is valid
    if (k > n)
        return -1;
 
    // Create and fill array to store cumulative
    // sum. csum[i] stores sum of arr[0] to arr[i]
    int *csum = new int[n];
    csum[0] = arr[0];
    for (int i=1; i max_sum)
        {
            max_sum = curr_sum;
            max_end = i;
        }
    }
 
    delete [] csum; // To avoid memory leak
 
    // Return starting index
    return max_end - k + 1;
}
 
// Driver program
int main()
{
    int arr[] = {-1, 10, -15, -6, 50, 3};
    int k = 4;
    int n = sizeof(arr)/sizeof(arr[0]);
    cout << "The maximum average subarray of "
         "length "<< k << " begins at index "
         << findMaxAverage(arr, n, k);
    return 0;
}

Output

The maximum average subarray of length 4 begins at index 1

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  • Construct a Binary Tree from Postorder and Inorder

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    • Searching in Binary Tree – C | C++ | Java
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  • Construct Tree from given Postorder and Inorder traversals – C | C++ | Java
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Introduction to Trees

Binary Trees

Binary Search Trees

Traversals

  • Traversal in Trees
  • Tree Traversals: Breadth-First Search (BFS) : C | C++ | Java
  • Tree Traversals: Depth First Search (DFS) : C | C++ | Java
  • Construct a Binary Tree from Postorder and Inorder

B – Trees

AVL Trees

  • AVL Trees
    • AVL Trees: Introduction
    • AVL Tree Insertion :  C | C++ | Java
    • AVL Tree Deletion : C | C++ | Java
    • Insertion in a Binary Tree (Level Order) – C | C++ | Java
    • Searching in Binary Tree – C | C++ | Java
    • Searching in a Binary Search Tree – C | C++ | Java

Complete Programs for Trees

  • Depth First Traversals – C | C++ | Java
  • Level Order Traversal – C | C++ | Java
  • Construct Tree from given Inorder and Preorder traversals – C | C++ | Java
  • Construct Tree from given Postorder and Inorder traversals – C | C++ | Java
  • Construct Tree from given Postorder and Preorder traversal – C | C++ | Java
  • Find size of the Binary tree – C | C++ | Java
  • Find the height of binary tree – C | C++ | Java
  • Find maximum in binary tree – C | C++ | Java
  • Check whether two tree are identical- C| C++| Java
  • Spiral Order traversal of Tree- C | C++| Java
  • Level Order Traversal LIne by Line – C | C++| Java
  • Hand shaking lemma and some Impotant Tree Properties.
  • Check If binary tree if Foldable or not.- C| C++| Java
  • check whether tree is Symmetric  C| C++| Java.
  • Check for Children-Sum in Binary Tree- C|C++| Java
  • Sum of all nodes in Binary Tree- C | C++ | Java
  • Lowest Common Ancestor in Binary Tree. C | C++ | Java