For the original problem description, pls checkout the image source at the very bottom of this web page š¾š¾
Imagine youāre in a magical world where certain numbers are considered "fancy." A number is fancy if, when written in base-4, it only contains the digits 0 and 1ālike secret codes known only to wizards. For example, 17 is fancy because its base-4 form, 101, uses only 0s and 1s, while 18 is not, as its base-4 form, 102, contains a forbidden 2. Now, your task is to discover how many of these special, fancy numbers exist below a given number, n. But beware! n can be as big as a billion, so you need a clever methodāsomething faster than just checking every number individually.
Example 1:
Input: n = 1
Output: 0
Explanation:There are no positive integers less than 1.
Example 2:
Input: n = 10
Output: 3
Explanation:The fancy numbers less than 10 are {1, 4, 5}.
TO-DO
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