0600. Non-negative Integers without Consecutive Ones

https://leetcode.com/problems/non-negative-integers-without-consecutive-ones

Description

Given a positive integer n, return the number of the integers in the range [0, n] whose binary representations do not contain consecutive ones.

Example 1:

**Input:** n = 5
**Output:** 5
**Explanation:**
Here are the non-negative integers <= 5 with their corresponding binary representations:
0 : 0
1 : 1
2 : 10
3 : 11
4 : 100
5 : 101
Among them, only integer 3 disobeys the rule (two consecutive ones) and the other 5 satisfy the rule. 

Example 2:

**Input:** n = 1
**Output:** 2

Example 3:

**Input:** n = 2
**Output:** 3

Constraints:

• 1 <= n <= 109

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