feat: add 002

Author: Blankj

README.md

@@ -46,7 +46,7 @@
 
 |#|Title|Tag|
 |:------------- |:------------- |:------------- |
-|2|Add Two Numbers|Linked List, Math|
+|2|[Add Two Numbers][002]|Linked List, Math|
 |8|[String to Integer (atoi)][008]|Math, String|
 |19|[Remove Nth Node From End of List][019]|Linked List, Two Pointers|
 
@@ -96,5 +96,8 @@
 [121]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/121/README.md
 [122]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/122/README.md
 
+[002]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/002/README.md
 [008]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/008/README.md
 [019]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/019/README.md
+
+[004]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/004/README.md

note/002/README.md

@@ -0,0 +1,60 @@
+# [Add Two Numbers][title]
+
+## Description
+
+You are given two **non-empty** linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.
+
+You may assume the two numbers do not contain any leading zero, except the number 0 itself.
+
+**Input:** (2 -> 4 -> 3) + (5 -> 6 -> 4)
+**Output:** 7 -> 0 -> 8
+
+**Tags:** Linked List, Math
+
+
+## 思路
+
+题意我也是看了好久才看懂，就是以链表表示一个数，低位在前，高位在后，所以题中的例子就是`342 + 465 = 807`，所以我们模拟计算即可。
+
+``` java
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ * int val;
+ * ListNode next;
+ * ListNode(int x) { val = x; }
+ * }
+ */
+class Solution {
+ public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
+ ListNode node = new ListNode(0);
+ ListNode n1 = l1, n2 = l2, t = node;
+ int sum = 0;
+ while (n1 != null || n2 != null) {
+ sum /= 10;
+ if (n1 != null) {
+ sum += n1.val;
+ n1 = n1.next;
+ }
+ if (n2 != null) {
+ sum += n2.val;
+ n2 = n2.next;
+ }
+ t.next = new ListNode(sum % 10);
+ t = t.next;
+ }
+ if (sum / 10 != 0) t.next = new ListNode(1);
+ return node.next;
+ }
+}
+```
+
+
+## 结语
+
+如果你同我一样热爱数据结构、算法、LeetCode，可以关注我GitHub上的LeetCode题解：[awesome-java-leetcode][ajl]
+
+
+
+[title]: https://leetcode.com/problems/add-two-numbers
+[ajl]: https://github.com/Blankj/awesome-java-leetcode

project/leetcode/.idea/workspace.xml

@@ -0,0 +1,27 @@
+package com.blankj.medium._002;
+
+import com.blankj.structure.ListNode;
+
+import java.util.Arrays;
+
+/**
+ * <pre>
+ * author: Blankj
+ * blog : http://blankj.com
+ * time : 2017/10/11
+ * desc :
+ * </pre>
+ */
+public class Solution {
+
+ public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
+
+ }
+
+
+ public static void main(String[] args) {
+ Solution solution = new Solution();
+
+ System.out.println(Arrays.toString(solution.addTwoNumbers(nums, target)));
+ }
+}