Given two arrays of positive integers. Select two sub-arrays of equal size from each array and calculate maximum possible OR sum of the two sub-arrays.
Note: Let f(x, l, r) is the OR sum of all the elements in the range [l, r] in array x.
Examples :
Input : A[] = {1, 2, 4, 3, 2} B[] = {2, 3, 3, 12, 1} Output : 22 Explanation: Here, one way to get maximum sum is to select sub-array [l = 2, r = 4] f(A, 2, 4) = 2|4|3 = 7 f(B, 2, 4) = 3|3|12 = 15 So, f(A, 2, 4) + f(B, 2, 4) = 7 + 15 = 22. This sum can be achieved in many other ways. Input : A[] = {1, 2, 2} B[] = {2, 1, 3} Output : 6
Observe the operation of Bitwise OR operator. If we take two integers X and Y, then (X|Y >= X). It can be proved by taking some examples. Lets derive a formula using the above equation.
and also
from the above two equations,
So, we get maximum sum when we take the OR of the whole array ->
Below is the implementation of above approach:
C++
// CPP program to find maximum OR sum #include <bits/stdc++.h> using namespace std; // function to find maximum OR sum void MaximumSum( int a[], int b[], int n) { int sum1 = 0, sum2 = 0; // OR sum of all the elements // in both arrays for ( int i = 0; i < n; i++) { sum1 |= a[i]; sum2 |= b[i]; } cout << sum1 + sum2 << endl; } // Driver Code int main() { int A[] = { 1, 2, 4, 3, 2 }; int B[] = { 2, 3, 3, 12, 1 }; int n = sizeof (A) / sizeof (A[0]); MaximumSum(A, B, n); return 0; } |
Java
// Java program to find maximum OR sum class GFG { // function to find maximum OR sum static void MaximumSum( int a[], int b[], int n) { int sum1 = 0 , sum2 = 0 ; // OR sum of all the elements // in both arrays for ( int i = 0 ; i < n; i++) { sum1 |= a[i]; sum2 |= b[i]; } System.out.println(sum1 + sum2); } // Driver code public static void main(String arg[]) { int A[] = { 1 , 2 , 4 , 3 , 2 }; int B[] = { 2 , 3 , 3 , 12 , 1 }; int n = A.length; MaximumSum(A, B, n); } } // This code is contributed by Anant Agarwal. |
Python3
# Python 3 program to # find maximum OR sum # function to find # maximum OR sum def MaximumSum(a, b, n): sum1 = 0 sum2 = 0 # OR sum of all the # elements in both arrays for i in range ( 0 , n): sum1 | = a[i] sum2 | = b[i] print (sum1 + sum2) # Driver Code A = [ 1 , 2 , 4 , 3 , 2 ] B = [ 2 , 3 , 3 , 12 , 1 ] n = len (A) MaximumSum(A, B, n) # This code is contributed by Smitha Dinesh Semwal |
C#
// C# program to find maximum OR sum using System; class GFG { // function to find maximum OR sum static void MaximumSum( int []a, int []b, int n) { int sum1 = 0, sum2 = 0; // OR sum of all the elements // in both arrays for ( int i = 0; i < n; i++) { sum1 |= a[i]; sum2 |= b[i]; } Console.WriteLine(sum1 + sum2); } // Driver code public static void Main() { int []A = {1, 2, 4, 3, 2}; int []B = {2, 3, 3, 12, 1}; int n = A.Length; MaximumSum(A, B, n); } } // This code is contributed by Vt_m. |
PHP
<?php // PHP program to find maximum OR sum // function to find maximum OR sum function MaximumSum( $a , $b , $n ) { $sum1 = 0; $sum2 = 0; // OR sum of all the elements // in both arrays for ( $i = 0; $i < $n ; $i ++) { $sum1 |= $a [ $i ]; $sum2 |= $b [ $i ]; } echo ( $sum1 + $sum2 ). "\n" ; } // Driver Code $A = array (1, 2, 4, 3, 2 ); $B = array (2, 3, 3, 12, 1 ); $n = sizeof( $A ) / sizeof( $A [0]); MaximumSum( $A , $B , $n ); // This code is contributed by mits ?> |
Javascript
<script> // JavaScript program to find maximum OR sum // function to find maximum OR sum function MaximumSum(a, b, n) { let sum1 = 0, sum2 = 0; // OR sum of all the elements // in both arrays for (let i = 0; i < n; i++) { sum1 |= a[i]; sum2 |= b[i]; } document.write(sum1 + sum2); } // Driver code let A = [1, 2, 4, 3, 2]; let B = [2, 3, 3, 12, 1]; let n = A.length; MaximumSum(A, B, n); </script> |
22
Time Complexity: O(n)
Auxiliary Space: O(1)
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