diff --git a/top-100-liked/35/leetcode_test.go b/top-100-liked/35/leetcode_test.go
new file mode 100644
index 0000000..9c192e8
--- /dev/null
+++ b/top-100-liked/35/leetcode_test.go
@@ -0,0 +1,90 @@
+package top100liked
+
+import (
+	"fmt"
+	"testing"
+)
+
+// https://leetcode.cn/problems/lru-cache/?envType=study-plan-v2&envId=top-100-liked
+
+type LN struct {
+	Key  int
+	Val  int
+	Prev *LN
+	Next *LN
+}
+
+type LRUCache struct {
+	length    int
+	capacity  int
+	dummyHead *LN
+	dummyTail *LN
+	kv        map[int]*LN
+}
+
+func Constructor(capacity int) LRUCache {
+	head := &LN{}
+	tail := &LN{}
+	head.Next = tail
+	tail.Prev = head
+	return LRUCache{
+		length:    0,
+		capacity:  capacity,
+		dummyHead: head,
+		dummyTail: tail,
+		kv:        make(map[int]*LN, capacity),
+	}
+}
+
+func (this *LRUCache) removeNode(node *LN) {
+	node.Prev.Next = node.Next
+	node.Next.Prev = node.Prev
+}
+
+func (this *LRUCache) addToHead(node *LN) {
+	node.Next = this.dummyHead.Next
+	node.Prev = this.dummyHead
+	this.dummyHead.Next.Prev = node
+	this.dummyHead.Next = node
+}
+
+func (this *LRUCache) Get(key int) int {
+	if node, ok := this.kv[key]; ok {
+		this.removeNode(node)
+		this.addToHead(node)
+		return node.Val
+	}
+	return -1
+}
+
+func (this *LRUCache) Put(key int, value int) {
+	if node, ok := this.kv[key]; ok {
+		node.Val = value
+		this.removeNode(node)
+		this.addToHead(node)
+		return
+	}
+	if this.length >= this.capacity {
+		lru := this.dummyTail.Prev
+		this.removeNode(lru)
+		delete(this.kv, lru.Key)
+	} else {
+		this.length++
+	}
+	newNode := &LN{Key: key, Val: value}
+	this.addToHead(newNode)
+	this.kv[key] = newNode
+}
+
+func Test1(t *testing.T) {
+	lRUCache := Constructor(2)
+	lRUCache.Put(1, 1)
+	lRUCache.Put(2, 2)
+	fmt.Println(lRUCache.Get(1))
+	lRUCache.Put(3, 3)
+	fmt.Println(lRUCache.Get(2))
+	lRUCache.Put(4, 4)
+	fmt.Println(lRUCache.Get(1))
+	fmt.Println(lRUCache.Get(3))
+	fmt.Println(lRUCache.Get(4))
+}
diff --git a/top-100-liked/36/leetcode_test.go b/top-100-liked/36/leetcode_test.go
new file mode 100644
index 0000000..0c3eccd
--- /dev/null
+++ b/top-100-liked/36/leetcode_test.go
@@ -0,0 +1,32 @@
+package top100liked
+
+import (
+	"testing"
+)
+
+// https://leetcode.cn/problems/binary-tree-inorder-traversal/?envType=study-plan-v2&envId=top-100-liked
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func inorderTraversal(root *TreeNode) []int {
+	if root == nil {
+		return []int{}
+	}
+	res := []int{}
+	if root.Left != nil {
+		res = append(res, inorderTraversal(root.Left)...)
+	}
+	res = append(res, root.Val)
+	if root.Right != nil {
+		res = append(res, inorderTraversal(root.Right)...)
+	}
+	return res
+}
+
+func Test1(t *testing.T) {
+
+}
diff --git a/top-100-liked/37/leetcode_test.go b/top-100-liked/37/leetcode_test.go
new file mode 100644
index 0000000..f603f17
--- /dev/null
+++ b/top-100-liked/37/leetcode_test.go
@@ -0,0 +1,34 @@
+package top100liked
+
+import (
+	"testing"
+)
+
+// https://leetcode.cn/problems/maximum-depth-of-binary-tree/description/?envType=study-plan-v2&envId=top-100-liked
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func maxDepth(root *TreeNode) int {
+	if root == nil {
+		return 0
+	}
+	if root.Left == nil && root.Right == nil {
+		return 1
+	}
+	md := 0
+	if root.Left != nil {
+		md = maxDepth(root.Left) + 1
+	}
+	if root.Right != nil {
+		md = max(maxDepth(root.Right)+1, md)
+	}
+	return md
+}
+
+func Test1(t *testing.T) {
+
+}
diff --git a/top-100-liked/38/leetcode_test.go b/top-100-liked/38/leetcode_test.go
new file mode 100644
index 0000000..f0fa0b3
--- /dev/null
+++ b/top-100-liked/38/leetcode_test.go
@@ -0,0 +1,27 @@
+package top100liked
+
+import (
+	"testing"
+)
+
+// https://leetcode.cn/problems/invert-binary-tree/description/?envType=study-plan-v2&envId=top-100-liked
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func invertTree(root *TreeNode) *TreeNode {
+	if root == nil {
+		return nil
+	}
+	root.Left, root.Right = root.Right, root.Left
+	invertTree(root.Left)
+	invertTree(root.Right)
+	return root
+}
+
+func Test1(t *testing.T) {
+
+}
diff --git a/top-100-liked/39/leetcode_test.go b/top-100-liked/39/leetcode_test.go
new file mode 100644
index 0000000..22b4e0e
--- /dev/null
+++ b/top-100-liked/39/leetcode_test.go
@@ -0,0 +1,31 @@
+package top100liked
+
+import (
+	"testing"
+)
+
+// https://leetcode.cn/problems/symmetric-tree/description/?envType=study-plan-v2&envId=top-100-liked
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func isSymmetric(root *TreeNode) bool {
+	return check(root.Left, root.Right)
+}
+
+func check(p, q *TreeNode) bool {
+	if p == nil && q == nil {
+		return true
+	}
+	if p == nil || q == nil {
+		return false
+	}
+	return p.Val == q.Val && check(p.Left, q.Right) && check(p.Right, q.Left)
+}
+
+func Test1(t *testing.T) {
+
+}
diff --git a/top-100-liked/40/leetcode_test.go b/top-100-liked/40/leetcode_test.go
new file mode 100644
index 0000000..789b6b0
--- /dev/null
+++ b/top-100-liked/40/leetcode_test.go
@@ -0,0 +1,13 @@
+package top100liked
+
+// https://leetcode.cn/problems/diameter-of-binary-tree/description/?envType=study-plan-v2&envId=top-100-liked
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func diameterOfBinaryTree(root *TreeNode) int {
+
+}