Description
Given n and start, return a permutation of integers 0 to 2^n - 1 starting with start where adjacent integers differ by one bit.
Examples
Input:
n = 2, start = 3Output:
[3,2,0,1]Explanation:
Gray code from 3.
Input:
n = 1, start = 1Output:
[1,0]Explanation:
For 1-bit Gray code starting from 1: there are only two possible values (0,1). Starting from 1, the Gray code sequence is [1,0] where each consecutive pair differs by exactly one bit.
Input:
n = 3, start = 0Output:
[0,1,3,2,6,7,5,4]Explanation:
For 3-bit Gray code starting from 0: the standard Gray code sequence [0,1,3,2,6,7,5,4] where each number differs from the next by exactly one bit. Binary representation: 000→001→011→010→110→111→101→100.
Constraints
- •
1 ≤ n ≤ 16