leetcode 9-回文数

/**
 * @param {number} x
 * @returns {boolean}
 * 判断一个整数是否是回文数。回文数是指正序（从左向右）和倒序（从右向左）读都是一样的整数。
 */


 function isPalindrome(x) {
    
    
  while(typeof x !== 'number' || x < 0){
    
    
    return false
  }
  console.log(reverse(x));
  return x == reverse(x) ? true : false
}


//  const num = 12345
 const num1 = 12321 

 const result = isPalindrome(num1)
 console.log(result);



 function reverse(x) {
    
    
  let num = x > 0? x.toString().split(''): (-x).toString().split('')
  let target =  x> 0?  true:  false
  const length = num.length
   if(typeof x === "number" && length >0 ){
    
    
     const index = Math.floor(length/2)
     for(let i =0; i<=index; i++) {
    
    
       temp = num[i]
       num[i] = num[length -i]
       num[length -i] = temp
     }
     target?  '': num[0] = '-'
     return num.join('')
   }
 }