9. 回文数

9. 回文数

代码

javascript

// 输入：x = 121
// 输出：true

export function isPalindrome(x) {
  if (x < 0) return false
  let num = x
  let res = 0
  while (num !== 0) {
    res = res * 10 + num % 10
    num = ~~(num / 10)
  }
  return res === x
}

typescript

// 输入：x = 121
// 输出：true

export function isPalindrome(x: number): boolean {
  if (x < 0) return false
  let num = x
  let res = 0
  while (num !== 0) {
    res = res * 10 + num % 10
    num = ~~(num / 10)
  }
  return res === x
}

测试代码

test

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

test(`121`, () => {
  expect(isPalindrome(121)).toEqual(true)
})

test(`121`, () => {
  expect(isPalindromeJs(121)).toEqual(true)
})