题目如下：

For a non-negative integer X, the array-form of X is an array of its digits in left to right order.  For example, if X = 1231, then the array form is [1,2,3,1].

Given the array-form A of a non-negative integer X, return the array-form of the integer X+K.

 

Example 1:

Input: A = [1,2,0,0], K = 34Output: [1,2,3,4]Explanation: 1200 + 34 = 1234

Example 2:

Input: A = [2,7,4], K = 181Output: [4,5,5]Explanation: 274 + 181 = 455

Example 3:

Input: A = [2,1,5], K = 806Output: [1,0,2,1]Explanation: 215 + 806 = 1021

Example 4:

Input: A = [9,9,9,9,9,9,9,9,9,9], K = 1Output: [1,0,0,0,0,0,0,0,0,0,0]Explanation: 9999999999 + 1 = 10000000000

 

Note：

1. 1 <= A.length <= 10000
2. 0 <= A[i] <= 9
3. 0 <= K <= 10000
4. If A.length > 1, then A[0] != 0

解题思路：题目很简单，但是在相加的过程中要注意进位。同时K > A的场景需要做特殊处理。

代码如下：

class Solution(object):    def addToArrayForm(self, A, K):        """        :type A: List[int]        :type K: int        :rtype: List[int]        """        carrier = 0        for i in range(len(A)-1,-1,-1):            remainder = K % 10            K = K/10            A[i] += (remainder + carrier)            if A[i] >= 10:                A[i] -= 10                carrier = 1            else:                carrier = 0        if carrier == 1 and K == 0:            A.insert(0,1)        elif K > 0:            K += carrier            while K > 0:                A.insert(0, K% 10)                carrier = 0                K = K/10        return A