Algorithm
Problem Name: 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.
Example 1:
Input: num = [1,2,0,0], k = 34 Output: [1,2,3,4] Explanation: 1200 + 34 = 1234
Example 2:
Input: num = [2,7,4], k = 181 Output: [4,5,5] Explanation: 274 + 181 = 455
Example 3:
Input: num = [2,1,5], k = 806 Output: [1,0,2,1] Explanation: 215 + 806 = 1021
Constraints:
1 <= num.length <= 1040 <= num[i] <= 9numdoes not contain any leading zeros except for the zero itself.1 <= k <= 104
Code Examples
#1 Code Example with Java Programming
Code -
Java Programming
class Solution {
public List addToArrayForm(int[] num, int k) {
int carry = 0;
int idx = num.length - 1;
List < Integer> result = new ArrayList<>();
while (idx >= 0 || carry > 0 || k > 0) {
int temp = k % 10 + carry + (idx >= 0 ? num[idx--] : 0);
result.add(temp % 10);
carry = temp / 10;
k /= 10;
}
Collections.reverse(result);
return result;
}
}
Input
num = [1,2,0,0], k = 34
Output
[1,2,3,4]
#2 Code Example with Javascript Programming
Code -
Javascript Programming
const addToArrayForm = function(num, k) {
const res = []
for(let i = num.length - 1; i >= 0; i--) {
const tmp = num[i] + k
res.push(tmp % 10)
k = ~~(tmp / 10)
}
while(k > 0) {
res.push(k % 10)
k = ~~(k / 10)
}
res.reverse()
return res
};
Input
num = [1,2,0,0], k = 34
Output
[1,2,3,4]
#3 Code Example with Python Programming
Code -
Python Programming
class Solution:
def addToArrayForm(self, A, K):
for i in range(len(A))[::-1]:
A[i], K = (A[i] + K) % 10, (A[i] + K) // 10
return [int(i) for i in str(K)] + A if K else A
Input
num = [2,7,4], k = 181
Output
[4,5,5]
#4 Code Example with C# Programming
Code -
C# Programming
using System.Collections.Generic;
namespace LeetCode
{
public class _0989_AddToArrayFormOfInteger
{
public IList < int> AddToArrayForm(int[] A, int K)
{
var result = new List<int>();
var carry = 0;
var i = A.Length - 1;
while (i >= 0 && K > 0)
{
var sum = A[i--] + K % 10 + carry;
K /= 10;
var digit = sum % 10;
carry = sum / 10;
result.Add(digit);
}
while (i >= 0)
{
var sum = A[i--] + carry;
var digit = sum % 10;
carry = sum / 10;
result.Add(digit);
}
while (K > 0)
{
var sum = K % 10 + carry;
K /= 10;
var digit = sum % 10;
carry = sum / 10;
result.Add(digit);
}
if (carry > 0)
result.Add(carry);
result.Reverse();
return result;
}
}
}
Input
num = [2,7,4], k = 181
Output
[4,5,5]