50. Pow(x, n)

50. Pow(x, n)

代码

javascript

// 50. Pow(x, n)：https://leetcode.cn/problems/powx-n/description/
// 输入：x = 2, n = 10
// 输出：1024

export function powxN (x, n) {
  function dfs (x, n) {
    if (n === 0) {
      return 1
    }
    const y = dfs(x, Math.floor(n / 2))
    return n % 2 === 0 ? y * y : y * y * x
  }
  return n >= 0 ? dfs(x, n) : 1 / dfs(x, Math.abs(n))
}

typescript

// 50. Pow(x, n)：https://leetcode.cn/problems/powx-n/description/
// 输入：x = 2, n = 10
// 输出：1024

export function powxN (x: number, n: number): number {
  function dfs (x: number, n: number): number {
    if (n === 0) {
      return 1
    }
    const y = dfs(x, Math.floor(n / 2))
    return n % 2 === 0 ? y * y : y * y * x
  }
  return n >= 0 ? dfs(x, n) : 1 / dfs(x, Math.abs(n))
}

测试代码

test

import { expect, test } from 'vitest'
import { powxN } from './typescript.ts'
import { powxN as powxNJs } from './javascript.js'

test(`powxN`, () => {
  expect(powxN(2, 10)).toBe(1024)
  expect(powxN(2, -2)).toBe(0.25)
})

test(`powxNJs`, () => {
  expect(powxNJs(2, 10)).toBe(1024)
  expect(powxNJs(2, -2)).toBe(0.25)
})