added Add to Array-Form of Integer (easy)

Author: minhyeong-joe

Easy/AddToArrayFormInteger/Driver.java

@@ -0,0 +1,15 @@
+package Easy.AddToArrayFormInteger;
+
+import java.util.Arrays;
+
+public class Driver {
+ 
+ public static void main(String[] args) {
+ Solution sol = new Solution();
+ int[] A = {1, 2};
+ int K = 298;
+ System.out.println("Input: A = " + Arrays.toString(A) + ", K = " + K );
+ System.out.println("Output: " + sol.addToArrayForm(A, K).toString()); 
+ }
+
+}

Easy/AddToArrayFormInteger/README.md

@@ -0,0 +1,39 @@
+
+# Add to Array-Form of Integer
+[Leetcode Link](https://leetcode.com/problems/add-to-array-form-of-integer/)
+
+## Problem:
+
+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:
+
+```
+Input: A = [1,2,0,0], K = 34
+Output: [1,2,3,4]
+Explanation: 1200 + 34 = 1234
+```
+```
+Input: A = [2,7,4], K = 181
+Output: [4,5,5]
+Explanation: 274 + 181 = 455
+```
+```
+Input: A = [2,1,5], K = 806
+Output: [1,0,2,1]
+Explanation: 215 + 806 = 1021
+```
+```
+Input: A = [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
+```
+
+## Note:
+
+- `1 <= A.length <= 10000`
+- `0 <= A[i] <= 9`
+- `0 <= K <= 10000`
+- If `A.length > 1`, then `A[0] != 0`

Easy/AddToArrayFormInteger/Solution.java

@@ -0,0 +1,36 @@
+package Easy.AddToArrayFormInteger;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Solution {
+
+ public List<Integer> addToArrayForm(int[] A, int K) {
+ // convert int[] into List<Integer> to deal with addition overflow (increase in size)
+ List<Integer> result = new ArrayList<>(A.length);
+ for (int digit: A) {
+ result.add(digit);
+ }
+ // System.out.println(result.toString());
+
+ // start from right-end add corresponding digit from K
+ for (int i = result.size()-1; i >=0; i--) {
+ int sum = result.get(i) + (K%10);
+ K /= 10;
+ // if sum overflows (>= 10), then add abudant to K, and only take the one's digit as final sum
+ if (sum >= 10) {
+ K += sum/10;
+ sum %= 10;
+ }
+ // System.out.println(sum);
+ result.set(i, sum);
+ }
+ // deal with the remaining K
+ while (K > 0) {
+ result.add(0, K%10);
+ K /= 10;
+ }
+ return result;
+ }
+ 
+}

Hard/MaximumScoreWords/Solution.java

@@ -1,8 +1,6 @@
 package Hard.MaximumScoreWords;
 
 import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;

README.md

@@ -34,6 +34,7 @@ Languages used: Java and Python
  - [Isomorphic Strings](Easy/IsomorphicStrings)
  - [Binary Prefix Divisible By 5](Easy/BinaryPrefixDivBy5)
  - [Rank Transform of an Array](Easy/RankTransformArray)
+ - [Add to Array-Form of Integer](Easy/AddToArrayFormInteger)
 - Medium
  - [Minimum Add to Make Parentheses Valid](Medium/MinimumAddtoMakeParenthesesValid)
  - [Distribute Coins in Binary Tree](Medium/DistributionCoinsInBinaryTree)