规范格式

leetcode/0445.Add-Two-Numbers-II/445. Add Two Numbers II.go

@@ -0,0 +1,69 @@
+package leetcode
+
+import (
+	"github.com/halfrost/LeetCode-Go/structures"
+)
+
+// ListNode define
+type ListNode = structures.ListNode
+
+/**
+ * Definition for singly-linked list.
+ * type ListNode struct {
+ *     Val int
+ *     Next *ListNode
+ * }
+ */
+func addTwoNumbers445(l1 *ListNode, l2 *ListNode) *ListNode {
+	if l1 == nil {
+		return l2
+	}
+	if l2 == nil {
+		return l1
+	}
+	l1Length := getLength(l1)
+	l2Length := getLength(l2)
+	newHeader := &ListNode{Val: 1, Next: nil}
+	if l1Length < l2Length {
+		newHeader.Next = addNode(l2, l1, l2Length-l1Length)
+	} else {
+		newHeader.Next = addNode(l1, l2, l1Length-l2Length)
+	}
+	if newHeader.Next.Val > 9 {
+		newHeader.Next.Val = newHeader.Next.Val % 10
+		return newHeader
+	}
+	return newHeader.Next
+}
+
+func addNode(l1 *ListNode, l2 *ListNode, offset int) *ListNode {
+	if l1 == nil {
+		return nil
+	}
+	var (
+		res, node *ListNode
+	)
+	if offset == 0 {
+		res = &ListNode{Val: l1.Val + l2.Val, Next: nil}
+		node = addNode(l1.Next, l2.Next, 0)
+	} else {
+		res = &ListNode{Val: l1.Val, Next: nil}
+		node = addNode(l1.Next, l2, offset-1)
+	}
+	if node != nil && node.Val > 9 {
+		res.Val++
+		node.Val = node.Val % 10
+	}
+	res.Next = node
+	return res
+}
+
+func getLength(l *ListNode) int {
+	count := 0
+	cur := l
+	for cur != nil {
+		count++
+		cur = cur.Next
+	}
+	return count
+}

leetcode/0445.Add-Two-Numbers-II/445. Add Two Numbers II_test.go

@@ -0,0 +1,81 @@
+package leetcode
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/halfrost/LeetCode-Go/structures"
+)
+
+type question445 struct {
+	para445
+	ans445
+}
+
+// para 是参数
+// one 代表第一个参数
+type para445 struct {
+	one     []int
+	another []int
+}
+
+// ans 是答案
+// one 代表第一个答案
+type ans445 struct {
+	one []int
+}
+
+func Test_Problem445(t *testing.T) {
+
+	qs := []question445{
+
+		question445{
+			para445{[]int{}, []int{}},
+			ans445{[]int{}},
+		},
+
+		question445{
+			para445{[]int{1}, []int{1}},
+			ans445{[]int{2}},
+		},
+
+		question445{
+			para445{[]int{1, 2, 3, 4}, []int{1, 2, 3, 4}},
+			ans445{[]int{2, 4, 6, 8}},
+		},
+
+		question445{
+			para445{[]int{1, 2, 3, 4, 5}, []int{1, 2, 3, 4, 5}},
+			ans445{[]int{2, 4, 6, 9, 0}},
+		},
+
+		question445{
+			para445{[]int{1}, []int{9, 9, 9, 9, 9}},
+			ans445{[]int{1, 0, 0, 0, 0, 0}},
+		},
+
+		question445{
+			para445{[]int{9, 9, 9, 9, 9}, []int{1}},
+			ans445{[]int{1, 0, 0, 0, 0, 0}},
+		},
+
+		question445{
+			para445{[]int{2, 4, 3}, []int{5, 6, 4}},
+			ans445{[]int{8, 0, 7}},
+		},
+
+		question445{
+			para445{[]int{1, 8, 3}, []int{7, 1}},
+			ans445{[]int{2, 5, 4}},
+		},
+		// 如需多个测试，可以复制上方元素。
+	}
+
+	fmt.Printf("------------------------Leetcode Problem 445------------------------\n")
+
+	for _, q := range qs {
+		_, p := q.ans445, q.para445
+		fmt.Printf("【input】:%v       【output】:%v\n", p, structures.List2Ints(addTwoNumbers445(structures.Ints2List(p.one), structures.Ints2List(p.another))))
+	}
+	fmt.Printf("\n\n\n")
+}

leetcode/0445.Add-Two-Numbers-II/README.md

@@ -0,0 +1,25 @@
+# [445. Add Two Numbers II](https://leetcode.com/problems/add-two-numbers-ii/)
+
+## 题目
+
+You are given two non-empty linked lists representing two non-negative integers. The most significant digit comes first 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.
+
+Follow up:
+What if you cannot modify the input lists? In other words, reversing the lists is not allowed.
+
+Example:
+
+```text
+Input: (7 -> 2 -> 4 -> 3) + (5 -> 6 -> 4)
+Output: 7 -> 8 -> 0 -> 7
+```
+
+## 题目大意
+
+这道题是第 2 题的变种题，第 2 题中的 2 个数是从个位逆序排到高位，这样相加只用从头交到尾，进位一直进位即可。这道题目中强制要求不能把链表逆序。2 个数字是从高位排到低位的，这样进位是倒着来的。
+
+## 解题思路
+
+思路也不难，加法只用把短的链表依次加到长的链表上面来就可以了，最终判断一下最高位有没有进位，有进位再往前进一位。加法的过程可以用到递归。