From dc808e4af58357d0afc011fcda88337dad291759 Mon Sep 17 00:00:00 2001
From: huangge1199 <huangge1199@hotmail.com>
Date: Fri, 19 Feb 2021 11:45:42 +0800
Subject: [PATCH] =?UTF-8?q?=E5=8A=9B=E6=89=A3=EF=BC=9A445.=20=E4=B8=A4?=
 =?UTF-8?q?=E6=95=B0=E7=9B=B8=E5=8A=A0=20II?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../study/t2021/t20210219/AddTwoNumbers.java  | 83 +++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 LeetCode/src/main/java/com/code/leet/study/t2021/t20210219/AddTwoNumbers.java

diff --git a/LeetCode/src/main/java/com/code/leet/study/t2021/t20210219/AddTwoNumbers.java b/LeetCode/src/main/java/com/code/leet/study/t2021/t20210219/AddTwoNumbers.java
new file mode 100644
index 0000000..c3a72e2
--- /dev/null
+++ b/LeetCode/src/main/java/com/code/leet/study/t2021/t20210219/AddTwoNumbers.java
@@ -0,0 +1,83 @@
+package com.code.leet.study.t2021.t20210219;
+
+import com.code.leet.entiy.ListNode;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 给你两个 非空 链表来代表两个非负整数。数字最高位位于链表开始位置。它们的每个节点只存储一位数字。将这两数相加会返回一个新的链表。
+ * <p>
+ * 你可以假设除了数字 0 之外，这两个数字都不会以零开头。
+ * <p>
+ * <p>
+ * <p>
+ * 进阶：
+ * <p>
+ * 如果输入链表不能修改该如何处理？换句话说，你不能对列表中的节点进行翻转。
+ * <p>
+ * <p>
+ * <p>
+ * 示例：
+ * <p>
+ * 输入：(7 -> 2 -> 4 -> 3) + (5 -> 6 -> 4)
+ * 输出：7 -> 8 -> 0 -> 7
+ */
+public class AddTwoNumbers {
+    /**
+     * 445. 两数相加 II
+     */
+    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
+        if (l1 == null) {
+            return l2;
+        }
+        if (l2 == null) {
+            return l1;
+        }
+        List<ListNode> list1 = new ArrayList<>();
+        List<ListNode> list2 = new ArrayList<>();
+        ListNode temp1 = l1;
+        ListNode temp2 = l2;
+        while (temp1 != null) {
+            list1.add(temp1);
+            temp1 = temp1.next;
+        }
+        while (temp2 != null) {
+            list2.add(temp2);
+            temp2 = temp2.next;
+        }
+        if (list1.size() > list2.size()) {
+            return add(list1,list2);
+        }else {
+            return add(list2,list1);
+        }
+    }
+
+    private ListNode add(List<ListNode> list1, List<ListNode> list2){
+        int sum = 0;
+        int size1 = list1.size();
+        int size2 = list2.size();
+        int i = 0;
+        for (; i < size2; i++) {
+            sum = list2.get(size2 - 1 - i).val + list1.get(size1 - 1 - i).val + sum;
+            list1.get(size1 - 1 - i).val = sum % 10;
+            sum = sum / 10;
+        }
+        while (sum > 0) {
+            if(size1 - 1 - i>=0){
+                sum = list1.get(size1 - 1 - i).val + sum;
+                list1.get(size1 - 1 - i).val = sum % 10;
+                sum = sum / 10;
+                i++;
+            }else{
+                break;
+            }
+        }
+        if(sum>0){
+            ListNode head = new ListNode(sum);
+            head.next = list1.get(0);
+            return head;
+        }
+        return list1.get(0);
+    }
+}