2023-02-15.md

题目

989. Add to Array-Form of Integer

The array-form of an integer num is an array representing its digits in left to right order.

• For example, for num = 1321, the array form is [1,3,2,1].

Given num, the array-form of an integer, and an integer k, return the array-form of the integer num + k.

思路

代码

// runtime 95.96% memory 96.89%
var addToArrayForm = function(num, k) {
  const kkk = String(k)
  let i = num.length - 1
  let j = kkk.length - 1
  let carry = 0
  while (j >= 0 || (i >= 0 && carry > 0)) {
    let sum = carry
    if (j >= 0) sum += kkk.charCodeAt(j--) - 48
    if (i >= 0) {
      sum += num[i]
      num[i--] = sum % 10
    } else {
      num.splice(0, 0, sum % 10)
    }
    carry = Math.floor(sum / 10)
  }
  if (carry) {
    num.splice(0, 0, carry)
  }
  return num
}