Second-Rightmost Zero Bit
Description
Implement the missing code, denoted by ellipses. You may not modify the pre-existing code.
Presented with the integer n, find the 0-based position of the second rightmost zero bit in its binary representation (it is guaranteed that such a bit exists), counting from right to left.
Return the value of 2position_of_the_found_bit.
Example
For n = 37, the output should be
secondRightmostZeroBit(n) = 8.
3710 = 1001012. The second rightmost zero bit is at position 3 (0-based) from the right in the binary representation of n.
Thus, the answer is 23 = 8.
Input/Output
-
[execution time limit] 4 seconds (js)
-
[input] integer n
Guaranteed constraints:
4 \leq n \leq 2^{30}. -
[output] integer
[JavaScript (ES6)] Syntax Tips
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// Prints help message to the console
// Returns a string
function helloWorld(name) {
console.log("This prints to the console when you Run Tests");
return "Hello, " + name;
}
Solution
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function secondRightmostZeroBit(n) {
return (
1 <<
(n.toString(2).length -
n.toString(2).lastIndexOf("0", n.toString(2).lastIndexOf("0") - 1) -
1)
);
}