LeetCode-in-Java
989. Add to Array-Form of Integer
Easy
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
Solution
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class Solution {
public List<Integer> addToArrayForm(int[] num, int k) {
ArrayList<Integer> result = new ArrayList<>();
int carry = 0;
for (int i = num.length - 1; i >= 0; i--) {
int temp = num[i] + k % 10 + carry;
result.add(temp % 10);
carry = temp / 10;
k /= 10;
}
while (k > 0) {
int t = k % 10 + carry;
result.add(t % 10);
carry = t / 10;
k /= 10;
}
if (carry == 1) {
result.add(1);
}
Collections.reverse(result);
return result;
}
}