HackerRank Coding Interview 8. Maximum Or-Sum

Time to complete — 30 minutes

Question Type = Medium

Asked in = Netflix, Amazon, Uber, Lyft, Bloomberg, Morgan Stanley, Apple, and Google, Synchrony.

Skills: arrays, bit manipulation, prefix array

Insights — It should be read very carefully read and you must ask questions in between.

Question —

For an array of n integers, arr[n], perform the following operation up to some integer k times.

• Choose an index i such that 1 ≤ i ≤ n.
• Replace arr[i] with arr[i]×2.

The or-sum is the bitwise-or of all elements in the final array after the operations. Return the maximum or-sum possible.

# HINT is below
# bitwise operators
 
a = 10
b = 4
 
# Print bitwise AND operation
print("a & b =", a & b)
 
# Print bitwise OR operation
print("a | b =", a | b)
 
# Print bitwise NOT operation
print("~a =", ~a)
 
# print bitwise XOR operation
print("a ^ b =", a ^ b)

HINT 

.....for Bitwise OR operation with integer 2 
.....K-times, is nothing but RIGHT shift the number K times.


Interger_value << k ==== K-times [Interger_value (bitwise-OR) 2 ]

Example

arr = [12, 9]

k = 1

These outcomes are possible after 1 operation.

1. Select i = 1 :