Given an array arr[] of N positive elements, the task is to find the maximum bitwise OR value of a pair from the given array.
Examples:
Input: arr[] = {3, 6, 8, 16}
Output: 24
Explanation:
The pair giving maximum OR value is (8, 16)
8|16 = 24
Input: arr[] = {8, 7, 3, 12}
Output: 15
Explanation:
There are more than one pair giving us the maximum OR value.
8|7 = 15
Naive Approach: Refer to Maximum OR value of a pair in an array for the naive approach.
Efficient Approach: In this article, we will discuss an optimized solution for the given problem.
Follow the steps below to solve the problem:
- Find the largest element from the array.
- Perform Bitwise OR between the largest element and the remaining array elements one by one. This is because the arrangement of set bits in the largest element will contribute to maximum OR value possible from array elements.
- Print the maximum OR value obtained performing the above step.
Below is the implementation of the above approach:
C++
// C++ implementation of// the approach above#include <bits/stdc++.h>using namespace std;// Function to return the maximum// bitwise OR for any pair of the// given array in O(n) time complexity.int maxOR(int arr[], int n){ // Find the maximum // element in the array int max_value = *max_element(arr, arr + n); // Stores the maximum // OR value int ans = 0; // Traverse the array and // perform Bitwise OR // between every array element // with the maximum element for (int i = 0; i < n; i++) { ans = max(ans, (max_value | arr[i])); } return ans;}// Driver Codeint main(){ int arr[] = { 3, 6, 8, 16 }; int n = sizeof(arr) / sizeof(arr[0]); cout << maxOR(arr, n); return 0;} |
Java
// Java implementation of// the approach aboveimport java.util.Arrays;class GFG{ // Function to return the maximum// bitwise OR for any pair of the// given array in O(n) time complexity.static int maxOR(int []arr, int n){ // Find the maximum // element in the array int max_value = Arrays.stream(arr).max().getAsInt(); // Stores the maximum // OR value int ans = 0; // Traverse the array and // perform Bitwise OR // between every array element // with the maximum element for (int i = 0; i < n; i++) { ans = Math.max(ans, (max_value | arr[i])); } return ans;}// Driver Codepublic static void main(String[] args){ int arr[] = new int[]{ 3, 6, 8, 16 }; int n = 4; System.out.print(maxOR(arr, n));}}// This code is contributed by Ritik Bansal |
Python3
# Python3 implementation of # the approach above # Function to return the maximum# bitwise OR for any pair of the# given array in O(n) time complexity.def maxOR(arr, n): # Find the maximum # element in max_value = max(arr) # Stores the maximum # OR value the array ans = 0 # Traverse the array and # perform Bitwise OR # between every array element # with the maximum element for i in range(n): ans = max(ans, (max_value | arr[i])) return ans# Driver Codeif __name__ == "__main__": arr = [ 3, 6, 8, 16 ] n = len(arr) print(maxOR(arr, n))# This code is contributed by jana_sayantan |
C#
// C# implementation of// the approach aboveusing System;using System.Linq;class GFG{ // Function to return the maximum// bitwise OR for any pair of the// given array in O(n) time complexity.static int maxOR(int []arr, int n){ // Find the maximum // element in the array int max_value = arr.Max(); // Stores the maximum // OR value int ans = 0; // Traverse the array and // perform Bitwise OR // between every array element // with the maximum element for(int i = 0; i < n; i++) { ans = Math.Max(ans, (max_value | arr[i])); } return ans;}// Driver Codepublic static void Main(String[] args){ int []arr = { 3, 6, 8, 16 }; int n = 4; Console.Write(maxOR(arr, n));}}// This code is contributed by 29AjayKumar |
Javascript
<script>// Javascript implementation of// the above approach // Function to return the maximum// bitwise OR for any pair of the// given array in O(n) time complexity.function maxOR(arr, n){ // Find the maximum // element in the array let max_value = Math.max(...arr); // Stores the maximum // OR value let ans = 0; // Traverse the array and // perform Bitwise OR // between every array element // with the maximum element for (let i = 0; i < n; i++) { ans = Math.max(ans, (max_value | arr[i])); } return ans;} // Driver Code let arr = [ 3, 6, 8, 16 ]; let n = 4; document.write(maxOR(arr, n));// This code is contributed by souravghosh0416.</script> |
Output:
24
Time Complexity: O(N)
Auxiliary Space: O(1)
