LeetCode_Gray Code

An n-bit gray code sequence is a sequence of 2ⁿ integers where:

Every integer is in the inclusive range [0, 2n - 1], The first integer is 0, An integer appears no more than once in the sequence, The binary representation of every pair of adjacent integers differs by exactly one bit, and The binary representation of the first and last integers differs by exactly one bit. Given an integer n, return any valid n-bit gray code sequence.

Example 1:

Example 2:

Constraints

• 1 <= n <= 16

Solution

const grayCode = function (n) {
  let answer = [0];
  for (let i = 1; i <= n; i++) {
    let len = answer.length;
    let shifted = 1 << (i - 1);
    for (let j = len - 1; j >= 0; j--) {
      answer.push(shifted + answer[j]);
    }
    console.log(i, shifted, answer);
  }
  return answer;
};