diff --git a/include/jianzhi_offer.h b/include/jianzhi_offer.h
index e05565d..190e0f0 100644
--- a/include/jianzhi_offer.h
+++ b/include/jianzhi_offer.h
@@ -22,6 +22,8 @@ class String {
 public:
     std::string replace_space(std::string s);
     bool is_number(std::string s);
+
+    std::string reverse_left_words(std::string s, int n);
 };
 
 class ListNode {
@@ -30,8 +32,48 @@ public:
     ListNode *next;
     ListNode(int x) : val(x), next(NULL) {}
     std::vector<int> reverse_print(ListNode *head);
-    void reverse_stack(ListNode *head, std::vector<int>& res);
-    void reverse(ListNode *head, std::vector<int>& res);
+    void reverse_stack(ListNode *head, std::vector<int> &res);
+    void reverse(ListNode *head, std::vector<int> &res);
+};
+
+
+class Node {
+public:
+    int val;
+    Node *next;
+    Node *random;
+
+    Node(int _val) {
+        val = _val;
+        next = NULL;
+        random = NULL;
+    }
+
+    /**
+     * 剑指 Offer 35. 复杂链表的复制
+     *
+     * @url   https://leetcode.cn/leetbook/read/illustration-of-algorithm/9p0yy1/
+     * @param head
+     * @return
+     */
+    Node* copy_random_list(Node* head);
+};
+
+/**
+ * 剑指 Offer 30. 包含 min 函数的栈
+ *
+ * @url: https://leetcode.cn/leetbook/read/illustration-of-algorithm/50bp33/
+ */
+class MinStack {
+public:
+    MinStack() = default;
+    void push(int x);
+    void pop();
+    int top();
+    int min();
+private:
+    std::stack<int> _stk;
+    std::stack<int> _min_stk;
 };
 
 }
\ No newline at end of file
diff --git a/src/jianzhi_offer/min_stack.cpp b/src/jianzhi_offer/min_stack.cpp
new file mode 100644
index 0000000..d894453
--- /dev/null
+++ b/src/jianzhi_offer/min_stack.cpp
@@ -0,0 +1,25 @@
+#include "jianzhi_offer.h"
+namespace yaha {
+void MinStack::push(int x) {
+    _stk.push(x);
+
+    if (_min_stk.empty() || _min_stk.top() >= x) {
+        _min_stk.push(x);
+    }
+}
+
+void MinStack::pop() {
+    if (_stk.top() == _min_stk.top()) {
+        _min_stk.pop();
+    }
+    _stk.pop();
+}
+
+int MinStack::top() {
+    return _stk.top();
+}
+
+int MinStack::min() {
+    return _min_stk.top();
+}
+}
\ No newline at end of file
diff --git a/src/jianzhi_offer/node.cpp b/src/jianzhi_offer/node.cpp
new file mode 100644
index 0000000..c95334c
--- /dev/null
+++ b/src/jianzhi_offer/node.cpp
@@ -0,0 +1,32 @@
+/**
+ * 剑指 Offer 35. 复杂链表的复制
+ *
+ * @url: https://leetcode.cn/leetbook/read/illustration-of-algorithm/9p0yy1/
+ */
+
+#include "jianzhi_offer.h"
+
+namespace yaha {
+Node *Node::copy_random_list(Node *head) {
+    if (head == nullptr) {
+        return nullptr;
+    }
+
+    // 创建一个新的变量用于存储head
+    Node *cur = head;
+    std::unordered_map<Node*, Node*> map;
+    while (cur) {
+        map[cur] = new Node(cur->val);
+        cur = cur->next;
+    }
+
+    cur = head;
+    while (cur) {
+        map[cur]->next = map[cur->next];
+        map[cur]->random = map[cur->random];
+        cur = cur->next;
+    }
+
+    return map[head];
+}
+}
diff --git a/src/jianzhi_offer/string.cpp b/src/jianzhi_offer/string.cpp
index d610edb..e437620 100644
--- a/src/jianzhi_offer/string.cpp
+++ b/src/jianzhi_offer/string.cpp
@@ -4,7 +4,7 @@ namespace yaha {
 std::string String::replace_space(std::string s) {
     std::string result;
     for (int i = 0; i < s.length(); ++i) {
-        if (s[i]!=' ') {
+        if (s[i] != ' ') {
             result += s[i];
         } else {
             result += "%20";
@@ -14,6 +14,10 @@ std::string String::replace_space(std::string s) {
 }
 
 bool String::is_number(std::string s) {
+    // 1. 判断是不是数字？
+    // 2. 判断小数
+    // 3. 判断指数
+
     for (int i = 0; i < s.length(); ++i) {
         if (s[i] >= '0' && s[i] <= '9') {
             return true;
diff --git a/tests/jianzhi_offer/min_stack_test.cpp b/tests/jianzhi_offer/min_stack_test.cpp
new file mode 100644
index 0000000..6f61291
--- /dev/null
+++ b/tests/jianzhi_offer/min_stack_test.cpp
@@ -0,0 +1,14 @@
+#include <gtest/gtest.h>
+
+#include "jianzhi_offer.h"
+
+TEST(MinStackTest, BasicAssertions) {
+    yaha::MinStack min_stack;
+    min_stack.push(-2);
+    min_stack.push(0);
+    min_stack.push(-3);
+    ASSERT_EQ(-3, min_stack.min());
+    ASSERT_EQ(-1, min_stack.top());
+    min_stack.pop();
+    ASSERT_EQ(-2, min_stack.min());
+}
diff --git a/tests/jianzhi_offer/node_test.cpp b/tests/jianzhi_offer/node_test.cpp
new file mode 100644
index 0000000..6783a0c
--- /dev/null
+++ b/tests/jianzhi_offer/node_test.cpp
@@ -0,0 +1,14 @@
+#include <gtest/gtest.h>
+
+#include "jianzhi_offer.h"
+TEST(NodeTest, TestCopyRandomList) {
+    yaha::Node *head = new yaha::Node(1);
+    head->next = new yaha::Node(2);
+    head->next->next = new yaha::Node(3);
+    head->next->next->next = new yaha::Node(4);
+
+    yaha::Node *copy = head->copy_random_list(head);
+    ASSERT_EQ(copy->val, 4);
+    delete copy;
+    delete head;
+}
\ No newline at end of file