isBitSet
Check if the nth bit of a number is set (i.e., is 1). The index n is 0-based from the right.
Examples
isBitSet(10, 0) → false
isBitSet(10, 3) → true
Starter code
function isBitSet(num, n) {
}
Complexity of the optimal solution
Time O(1), space O(1). A mask is created by left-shifting 1 by n bits. The bitwise AND with the original number will be non-zero only if the nth bit was set. This is a constant time operation.