Add To Array-Form Of Integer Problem

Description

LeetCode Problem 989.

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.

Example 1:

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Input: num = [1,2,0,0], k = 34
Output: [1,2,3,4]
Explanation: 1200 + 34 = 1234
``````

Example 2:

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Input: num = [2,7,4], k = 181
Output: [4,5,5]
Explanation: 274 + 181 = 455
``````

Example 3:

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Input: num = [2,1,5], k = 806
Output: [1,0,2,1]
Explanation: 215 + 806 = 1021
``````

Example 4:

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Input: num = [9,9,9,9,9,9,9,9,9,9], k = 1
Output: [1,0,0,0,0,0,0,0,0,0,0]
Explanation: 9999999999 + 1 = 10000000000
``````

Constraints:

• 1 <= num.length <= 10^4
• 0 <= num[i] <= 9
• numdoes not contain any leading zeros except for the zero itself.
• 1 <= k <= 10^4

Sample C++ Code

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class Solution {
public:
vector<int> addToArrayForm(vector<int> A, int K) {
for (int i = A.size() - 1; i >= 0 && K > 0; i--) {
A[i] += K;
K = A[i] / 10;
A[i] %= 10;
}
while (K > 0) {
A.insert(A.begin(), K % 10);
K /= 10;
}
return A;
}
};
``````