js版数据结构与算法—3.8格雷编码

export default (n) => {
  // 递归函数，用来算输入为n的格雷编码序列
  let make = (n) => {
    if (n === 1) {
      return ['0', '1']
    } else {
      let prev = make(n - 1)
      let result = []
      let max = Math.pow(2, n) - 1
      for (let i = 0, len = prev.length; i < len; i++) {
        result[i] = `0${prev[i]}`
        result[max - i] = `1${prev[i]}`
      }
      return result
    }
  }
  return make(n)
}

import grayCode from '../../code/array/lesson4'

test('grayCode:1', () => {
  expect(grayCode(2)).toEqual(['00', '01', '11', '10'])
})
test('grayCode:2', () => {
  expect(grayCode(3)).toEqual(['000', '001', '011', '010', '110', '111', '101', '100'])
})