Binary Gap — LeetCode 868 Python Solution

The problem

Given a positive integer n, find and return the longest distance between any two adjacent 1's in the binary representation of n. If there are no two adjacent 1's, return 0.

Example

Input

n = 22

Output

2

Explanation

22 in binary is "10110".

Python solution

class Solution:
    def binaryGap(self, n: int) -> int:
        ans = 0
        pre, cur = inf, 0
        while n:
            if n & 1:
                ans = max(ans, cur - pre)
                pre = cur
            cur += 1
            n >>= 1
        return ans

Complexity

Pattern: Bit Manipulation

Use XOR, masks and the low-bit trick to replace whole data structures with an integer. LeetCode 868. Binary Gap is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Bit Manipulation.

The bit manipulation guide has the Python template for the pattern and the 194 LeetCode problems that use it.

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