diff --git a/.gitignore b/.gitignore
index 54c0e4a..fbf1224 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,5 +7,6 @@
 # mkdocs files
 overrides/
 site/
-codes/
+codes/python
+codes/cpp
 docs/chapter_*
\ No newline at end of file
diff --git a/codes/java/chapter_array_and_linkedlist/array.java b/codes/java/chapter_array_and_linkedlist/array.java
new file mode 100644
index 0000000..1a1c673
--- /dev/null
+++ b/codes/java/chapter_array_and_linkedlist/array.java
@@ -0,0 +1,100 @@
+package chapter_array_and_linkedlist;
+
+import java.util.*;
+import java.util.concurrent.ThreadLocalRandom;
+
+public class array {
+    /* 随机返回一个数组元素 */
+    static int randomAccess(int[] nums) {
+        // 在区间 [0, nums.length) 中随机抽取一个数字
+        int randomIndex = ThreadLocalRandom.current().
+                          nextInt(0, nums.length);
+        // 获取并返回随机元素
+        int randomNum = nums[randomIndex];
+        return randomNum;
+    }
+
+    /* 扩展数组长度 */
+    static int[] extend(int[] nums, int enlarge) {
+        // 初始化一个扩展长度后的数组
+        int[] res = new int[nums.length + enlarge];
+        // 将原数组中的所有元素复制到新数组
+        for (int i = 0; i < nums.length; i++) {
+            res[i] = nums[i];
+        }
+        // 返回扩展后的新数组
+        return res;
+    }
+
+    /* 在数组的索引 index 处插入元素 num */
+    static void insert(int[] nums, int num, int index) {
+        // 把索引 index 以及之后的所有元素向后移动一位
+        for (int i = nums.length - 1; i >= index; i--) {
+            nums[i] = nums[i - 1];
+        }
+        // 将 num 赋给 index 处元素
+        nums[index] = num;
+    }
+
+    /* 删除索引 index 处元素 */
+    static void remove(int[] nums, int index) {
+        // 把索引 index 之后的所有元素向前移动一位
+        for (int i = index; i < nums.length - 1; i++) {
+            nums[i] = nums[i + 1];
+        }
+    }
+
+    /* 遍历数组 */
+    static void traverse(int[] nums) {
+        int count = 0;
+        // 通过索引遍历数组
+        for (int i = 0; i < nums.length; i++) {
+            count++;
+        }
+        // 直接遍历数组
+        for (int num : nums) {
+            count++;
+        }
+    }
+
+    /* 在数组中查找指定元素 */
+    static int find(int[] nums, int target) {
+        for (int i = 0; i < nums.length; i++) {
+            if (nums[i] == target)
+                return i;
+        }
+        return -1;
+    }
+
+    /* Driver Code */
+    public static void main(String[] args) {
+        /* 初始化数组 */
+        int[] arr = new int[5];
+        System.out.println("数组 arr = " + Arrays.toString(arr));
+        int[] nums = { 1, 3, 2, 5, 4 };
+        System.out.println("数组 nums = " + Arrays.toString(nums));
+        
+        /* 随机访问 */
+        int randomNum = randomAccess(nums);
+        System.out.println("在 nums 中获取随机元素 " + randomNum);
+        
+        /* 长度扩展 */
+        nums = extend(nums, 3);
+        System.out.println("将数组长度扩展至 8 ，得到 nums = " + Arrays.toString(nums));
+        
+        /* 插入元素 */
+        insert(nums, 6, 3);
+        System.out.println("在索引 3 处插入数字 6 ，得到 nums = " + Arrays.toString(nums));
+
+        /* 删除元素 */
+        remove(nums, 2);
+        System.out.println("删除索引 2 处的元素，得到 nums = " + Arrays.toString(nums));
+        
+        /* 遍历数组 */
+        traverse(nums);
+        
+        /* 查找元素 */
+        int index = find(nums, 3);
+        System.out.println("在 nums 中查找元素 3 ，得到索引 = " + index);
+    }
+}
diff --git a/codes/java/chapter_array_and_linkedlist/linked_list.java b/codes/java/chapter_array_and_linkedlist/linked_list.java
new file mode 100644
index 0000000..9a1dedb
--- /dev/null
+++ b/codes/java/chapter_array_and_linkedlist/linked_list.java
@@ -0,0 +1,80 @@
+package chapter_array_and_linkedlist;
+
+import include.*;
+
+public class linked_list {
+    /* 在链表的结点 n0 之后插入结点 P */
+    static void insert(ListNode n0, ListNode P) {
+        ListNode n1 = n0.next;
+        n0.next = P;
+        P.next = n1;
+    }
+
+    /* 删除链表的结点 n0 之后的首个结点 */
+    static void remove(ListNode n0) {
+        if (n0.next == null)
+            return;
+        // n0 -> P -> n1
+        ListNode P = n0.next;
+        ListNode n1 = P.next;
+        n0.next = n1;
+    }
+
+    /* 访问链表中索引为 index 的结点 */
+    static ListNode access(ListNode head, int index) {
+        for (int i = 0; i < index; i++) {
+            head = head.next;
+            if (head == null)
+                return null;
+        }
+        return head;
+    }
+
+    /* 在链表中查找值为 target 的首个结点 */
+    static int find(ListNode head, int target) {
+        int index = 0;
+        while (head != null) {
+            if (head.val == target)
+                return index;
+            head = head.next;
+            index++;
+        }
+        return -1;
+    }
+
+    /* Driver Code */
+    public static void main(String[] args) {
+        /* 初始化链表 */
+        // 初始化各个结点 
+        ListNode n0 = new ListNode(1);
+        ListNode n1 = new ListNode(3);
+        ListNode n2 = new ListNode(2);
+        ListNode n3 = new ListNode(5);
+        ListNode n4 = new ListNode(4);
+        // 构建引用指向
+        n0.next = n1;
+        n1.next = n2;
+        n2.next = n3;
+        n3.next = n4;
+        System.out.println("初始化的链表为");
+        PrintUtil.printLinkedList(n0);
+
+        /* 插入结点 */
+        insert(n0, new ListNode(0));
+        System.out.println("插入结点后的链表为");
+        PrintUtil.printLinkedList(n0);
+
+        /* 删除结点 */
+        remove(n0);
+        System.out.println("删除结点后的链表为");
+        PrintUtil.printLinkedList(n0);
+
+        /* 访问结点 */
+        ListNode node = access(n0, 3);
+        System.out.println("链表中索引 3 处的结点的值 = " + node.val);
+
+        /* 查找结点 */
+        int index = find(n0, 2);
+        System.out.println("链表中值为 2 的结点的索引 = " + index);
+    }
+}
diff --git a/codes/java/chapter_array_and_linkedlist/list.java b/codes/java/chapter_array_and_linkedlist/list.java
new file mode 100644
index 0000000..1a478ea
--- /dev/null
+++ b/codes/java/chapter_array_and_linkedlist/list.java
@@ -0,0 +1,62 @@
+package chapter_array_and_linkedlist;
+
+import java.util.*;
+
+public class list {
+    public static void main(String[] args) {
+        /* 初始化列表 */
+        // 注意数组的元素类型是 int[] 的包装类 Integer[]
+        Integer[] numbers = new Integer[] { 1, 3, 2, 5, 4 };
+        List<Integer> list = new ArrayList<>(Arrays.asList(numbers));
+        System.out.println("列表 list = " + Arrays.toString(list.toArray()));
+
+        /* 访问元素 */
+        int num = list.get(1);
+        System.out.println("访问索引 1 处的元素，得到 num = " + num);
+
+        /* 更新元素 */
+        list.set(1, 0);
+        System.out.println("将索引 1 处的元素更新为 0 ，得到 list = " + Arrays.toString(list.toArray()));
+
+        /* 清空列表 */
+        list.clear();
+        System.out.println("清空列表后 list = " + Arrays.toString(list.toArray()));
+
+        /* 尾部添加元素 */
+        list.add(1);
+        list.add(3);
+        list.add(2);
+        list.add(5);
+        list.add(4);
+        System.out.println("添加元素后 list = " + Arrays.toString(list.toArray()));
+
+        /* 中间插入元素 */
+        list.add(3, 6);
+        System.out.println("在索引 3 处插入数字 6 ，得到 list = " + Arrays.toString(list.toArray()));
+
+        /* 删除元素 */
+        list.remove(3);
+        System.out.println("删除索引 3 处的元素，得到 list = " + Arrays.toString(list.toArray()));
+
+        /* 通过索引遍历列表 */
+        int count = 0;
+        for (int i = 0; i < list.size(); i++) {
+            count++;
+        }
+
+        /* 直接遍历列表元素 */
+        count = 0;
+        for (int n : list) {
+            count++;
+        }
+
+        /* 拼接两个列表 */
+        List<Integer> list1 = new ArrayList<>(Arrays.asList(new Integer[] { 6, 8, 7, 10, 9 }));
+        list.addAll(list1);
+        System.out.println("将列表 list1 拼接到 list 之后，得到 list = " + Arrays.toString(list.toArray()));
+
+        /* 排序列表 */
+        Collections.sort(list);
+        System.out.println("排序列表后 list = " + Arrays.toString(list.toArray()));
+    }
+}
diff --git a/codes/java/chapter_array_and_linkedlist/my_list.java b/codes/java/chapter_array_and_linkedlist/my_list.java
new file mode 100644
index 0000000..67b2554
--- /dev/null
+++ b/codes/java/chapter_array_and_linkedlist/my_list.java
@@ -0,0 +1,136 @@
+package chapter_array_and_linkedlist;
+
+import java.util.*;
+
+/* 列表类简易实现 */
+class MyList {
+    int[] nums;               // 数组（存储列表元素）
+    int initialCapacity = 10; // 列表初始容量
+    int size = 0;             // 列表长度（即当前元素数量）
+    int extendRatio = 2;      // 每次列表扩容的倍数
+
+    /* 构造函数 */
+    public MyList() {
+        nums = new int[initialCapacity];
+    }
+
+    /* 获取列表容量 */
+    public int size() {
+        return size;
+    }
+
+    /* 获取列表长度（即当前元素数量） */
+    public int capacity() {
+        return nums.length;
+    }
+
+    /* 访问元素 */
+    public int get(int index) {
+        // 索引如果越界则抛出异常，下同
+        if (index >= size)
+            throw new IndexOutOfBoundsException("索引越界");
+        return nums[index];
+    }
+
+    /* 更新元素 */
+    public void set(int index, int num) {
+        if (index >= size)
+            throw new IndexOutOfBoundsException("索引越界");
+        nums[index] = num;
+    }
+
+    /* 尾部添加元素 */
+    public void add(int num) {
+        // 元素数量超出容量时，触发扩容机制
+        if (size == nums.length)
+            extendCapacity();
+        nums[size] = num;
+        // 更新元素数量
+        size++;
+    }
+
+    /* 中间插入元素 */
+    public void add(int index, int num) {
+        if (index >= size)
+            throw new IndexOutOfBoundsException("索引越界");
+        // 元素数量超出容量时，触发扩容机制
+        if (size == nums.length)
+            extendCapacity();
+        // 索引 i 以及之后的元素都向后移动一位
+        for (int j = size - 1; j >= index; j--) {
+            nums[j + 1] = nums[j];
+        }
+        nums[index] = num;
+        // 更新元素数量
+        size++;
+    }
+
+    /* 删除元素 */
+    public void remove(int index) {
+        if (index >= size)
+            throw new IndexOutOfBoundsException("索引越界");
+        // 索引 i 之后的元素都向前移动一位
+        for (int j = index; j < size - 1; j++) {
+            nums[j] = nums[j + 1];
+        }
+        // 更新元素数量
+        size--;
+    }
+
+    /* 列表扩容 */
+    public void extendCapacity() {
+        // 新建一个长度为 size 的数组，并将原数组拷贝到新数组
+        nums = Arrays.copyOf(nums, nums.length * extendRatio);
+    }
+
+    /* 将列表转换为数组 */
+    public int[] toArray() {
+        int size = size();
+        // 仅转换有效长度范围内的列表元素
+        int[] nums = new int[size];
+        for (int i = 0; i < size; i++) {
+            nums[i] = get(i);
+        }
+        return nums;
+    }
+}
+
+public class my_list {
+    /* Driver Code */
+    public static void main(String[] args) {
+        /* 初始化列表 */
+        MyList list = new MyList();
+        /* 尾部添加元素 */
+        list.add(1);
+        list.add(3);
+        list.add(2);
+        list.add(5);
+        list.add(4);
+        System.out.println("列表 list = " + Arrays.toString(list.toArray()) +
+                           " ，容量 = " + list.capacity() + " ，长度 = " + list.size());
+
+        /* 中间插入元素 */
+        list.add(3, 6);
+        System.out.println("在索引 3 处插入数字 6 ，得到 list = " + Arrays.toString(list.toArray()));
+
+        /* 删除元素 */
+        list.remove(3);
+        System.out.println("删除索引 3 处的元素，得到 list = " + Arrays.toString(list.toArray()));
+
+        /* 访问元素 */
+        int num = list.get(1);
+        System.out.println("访问索引 1 处的元素，得到 num = " + num);
+
+        /* 更新元素 */
+        list.set(1, 0);
+        System.out.println("将索引 1 处的元素更新为 0 ，得到 list = " + Arrays.toString(list.toArray()));
+
+        /* 测试扩容机制 */
+        for (int i = 0; i < 10; i++) {
+            // 在 i = 5 时，列表长度将超出列表容量，此时触发扩容机制
+            list.add(i);
+        }
+        System.out.println("扩容后的列表 list = " + Arrays.toString(list.toArray()) +
+                           " ，容量 = " + list.capacity() + " ，长度 = " + list.size());
+    }
+}
diff --git a/codes/java/chapter_computational_complexity/space_complexity/space_complexity_types.java b/codes/java/chapter_computational_complexity/space_complexity/space_complexity_types.java
new file mode 100644
index 0000000..fdbf3b7
--- /dev/null
+++ b/codes/java/chapter_computational_complexity/space_complexity/space_complexity_types.java
@@ -0,0 +1,100 @@
+package chapter_computational_complexity.space_complexity;
+
+import include.*;
+import java.util.*;
+
+public class space_complexity_types {
+    /* 函数 */
+    static int function() {
+        // do something
+        return 0;
+    }
+    
+    /* 常数阶 */
+    static void constant(int n) {
+        // 常量、变量、对象占用 O(1) 空间
+        final int a = 0;
+        int b = 0;
+        int[] nums = new int[10000];
+        ListNode node = new ListNode(0);
+        // 循环中的变量占用 O(1) 空间
+        for (int i = 0; i < n; i++) {
+            int c = 0;
+        }
+        // 循环中的函数占用 O(1) 空间
+        for (int i = 0; i < n; i++) {
+            function();
+        }
+    }
+
+    /* 线性阶 */
+    static void linear(int n) {
+        // 长度为 n 的数组占用 O(n) 空间
+        int[] nums = new int[n];
+        // 长度为 n 的列表占用 O(n) 空间
+        List<ListNode> nodes = new ArrayList<>();
+        for (int i = 0; i < n; i++) {
+            nodes.add(new ListNode(i));
+        }
+        // 长度为 n 的哈希表占用 O(n) 空间
+        Map<Integer, String> map = new HashMap<>();
+        for (int i = 0; i < n; i++) {
+            map.put(i, String.valueOf(i));
+        }
+    }
+
+    /* 线性阶（递归实现） */
+    static void linearRecur(int n) {
+        System.out.println("递归 n = " + n);
+        if (n == 1) return;
+        linearRecur(n - 1);
+    }
+
+    /* 平方阶 */
+    static void quadratic(int n) {
+        // 矩阵占用 O(n^2) 空间
+        int numMatrix[][] = new int[n][n];
+        // 二维列表占用 O(n^2) 空间
+        List<List<Integer>> numList = new ArrayList<>();
+        for (int i = 0; i < n; i++) {
+            List<Integer> tmp = new ArrayList<>();
+            for (int j = 0; j < n; j++) {
+                tmp.add(0);
+            }
+            numList.add(tmp);
+        }
+    }
+
+    /* 平方阶（递归实现） */
+    static int quadraticRecur(int n) {
+        if (n <= 0) return 0;
+        int[] nums = new int[n];
+        System.out.println("递归 n = " + n + " 中的 nums 长度 = " + nums.length);
+        return quadraticRecur(n - 1);
+    }
+
+    /* 指数阶（建立满二叉树） */
+    static TreeNode buildTree(int n) {
+        if (n == 0) return null;
+        TreeNode root = new TreeNode(0);
+        root.left = buildTree(n - 1);
+        root.right = buildTree(n - 1);
+        return root;
+    }
+
+    /* Driver Code */
+    public static void main(String[] args) {
+        int n = 5;
+        // 常数阶
+        constant(n);
+        // 线性阶
+        linear(n);
+        linearRecur(n);
+        // 平方阶
+        quadratic(n);
+        quadraticRecur(n);
+        // 指数阶
+        TreeNode tree = buildTree(n);
+        PrintUtil.printTree(tree);
+    }
+}
diff --git a/codes/java/chapter_computational_complexity/space_time_tradeoff/leetcode_two_sum.java b/codes/java/chapter_computational_complexity/space_time_tradeoff/leetcode_two_sum.java
new file mode 100644
index 0000000..786574d
--- /dev/null
+++ b/codes/java/chapter_computational_complexity/space_time_tradeoff/leetcode_two_sum.java
@@ -0,0 +1,47 @@
+package chapter_computational_complexity.space_time_tradeoff;
+
+import java.util.*;
+
+class solution_brute_force {
+    public int[] twoSum(int[] nums, int target) {
+        int size = nums.length;
+        for (int i = 0; i < size - 1; i++) {
+            for (int j = i + 1; j < size; j++) {
+                if (nums[i] + nums[j] == target)
+                    return new int[] { i, j };
+            }
+        }
+        return new int[0];
+    }
+}
+
+class solution_hash_map {
+    public int[] twoSum(int[] nums, int target) {
+        int size = nums.length;
+        Map<Integer, Integer> dic = new HashMap<>();
+        for (int i = 0; i < size; i++) {
+            if (dic.containsKey(target - nums[i])) {
+                return new int[] { dic.get(target - nums[i]), i };
+            }
+            dic.put(nums[i], i);
+        }
+        return new int[0];
+    }
+}
+
+public class leetcode_two_sum {
+    public static void main(String[] args) {
+        // ======= Test Case =======
+        int[] nums = { 2,7,11,15 };
+        int target = 9;
+        
+        // ====== Driver Code ======
+        solution_brute_force slt1 = new solution_brute_force();
+        int[] res = slt1.twoSum(nums, target);
+        System.out.println(Arrays.toString(res));
+
+        solution_hash_map slt2 = new solution_hash_map();
+        res = slt2.twoSum(nums, target);
+        System.out.println(Arrays.toString(res));
+    }
+}
diff --git a/codes/java/chapter_computational_complexity/time_complexity/time_complexity_types.java b/codes/java/chapter_computational_complexity/time_complexity/time_complexity_types.java
new file mode 100644
index 0000000..f395694
--- /dev/null
+++ b/codes/java/chapter_computational_complexity/time_complexity/time_complexity_types.java
@@ -0,0 +1,149 @@
+package chapter_computational_complexity.time_complexity;
+
+public class time_complexity_types {
+    /* 常数阶 */
+    static int constant(int n) {
+        int count = 0;
+        int size = 100000;
+        for (int i = 0; i < size; i++)
+            count++;
+        return count;
+    }
+
+    /* 线性阶 */
+    static int linear(int n) {
+        int count = 0;
+        for (int i = 0; i < n; i++)
+            count++;
+        return count;
+    }
+    
+    /* 线性阶（遍历数组） */
+    static int arrayTraversal(int[] nums) {
+        int count = 0;
+        // 循环次数与数组长度成正比
+        for (int num : nums) {
+            // System.out.println(num);
+            count++;
+        }
+        return count;
+    }
+
+    /* 平方阶 */
+    static int quadratic(int n) {
+        int count = 0;
+        for (int i = 0; i < n; i++) {
+            for (int j = 0; j < n; j++) {
+                count++;
+            }
+        }
+        return count;
+    }
+
+    /* 平方阶（冒泡排序） */
+    static void bubbleSort(int[] nums) {
+        int n = nums.length;
+        for (int i = 0; i < n - 1; i++) {
+            for (int j = 0; j < n - 1 - i; j++) {
+                if (nums[j] > nums[j + 1]) {
+                    // 交换 nums[j] 和 nums[j + 1]
+                    int tmp = nums[j];
+                    nums[j] = nums[j + 1];
+                    nums[j + 1] = tmp;
+                }
+            }
+        }
+    }
+
+    /* 指数阶（循环实现） */
+    static int exponential(int n) {
+        int count = 0, base = 1;
+        // cell 每轮一分为二，形成数列 1, 2, 4, 8, ..., 2^(n-1)
+        for (int i = 0; i < n; i++) {
+            for (int j = 0; j < base; j++) {
+                count++;
+            }
+            base *= 2;
+        }
+        // count = 1 + 2 + 4 + 8 + .. + 2^(n-1) = 2^n - 1
+        return count;
+    }
+
+    /* 指数阶（递归实现） */
+    static int expRecur(int n) {
+        if (n == 1) return 1;
+        return expRecur(n - 1) + expRecur(n - 1) + 1;
+    }
+
+    /* 对数阶（循环实现） */
+    static int logarithmic(float n) {
+        int count = 0;
+        while (n > 1) {
+            n = n / 2;
+            count++;
+        }
+        return count;
+    }
+
+    /* 对数阶（递归实现） */
+    static int logRecur(float n) {
+        if (n <= 1) return 0;
+        return logRecur(n / 2) + 1;
+    }
+
+    /* 线性对数阶 */
+    static int linearLogRecur(float n) {
+        if (n <= 1) return 1;
+        int count = linearLogRecur(n / 2) + 
+                    linearLogRecur(n / 2);
+        for (int i = 0; i < n; i++) {
+            count++;
+        }
+        return count;
+    }
+
+    /* 阶乘阶（递归实现） */
+    static int factorialRecur(int n) {
+        if (n == 0) return 1;
+        int count = 0;
+        // 从 1 个分裂出 n 个
+        for (int i = 0; i < n; i++) {
+            count += factorialRecur(n - 1);
+        }
+        return count;
+    }
+
+    /* Driver Code */
+    public static void main(String[] args) {
+        // 可以修改 n 运行，体会一下各种复杂度的操作数量变化趋势
+        int n = 8;
+        System.out.println("输入数据大小 n = " + n);
+
+        int count = constant(n);
+        System.out.println("常数阶的计算操作数量 = " + count);
+
+        count = linear(n);
+        System.out.println("线性阶的计算操作数量 = " + count);
+        count = arrayTraversal(new int[n]);
+        System.out.println("线性阶（遍历数组）的计算操作数量 = " + count);
+
+        count = quadratic(n);
+        System.out.println("平方阶的计算操作数量 = " + count);
+
+        count = exponential(n);
+        System.out.println("指数阶（循环实现）的计算操作数量 = " + count);
+        count = expRecur(n);
+        System.out.println("指数阶（递归实现）的计算操作数量 = " + count);
+
+        count = logarithmic((float) n);
+        System.out.println("对数阶（循环实现）的计算操作数量 = " + count);
+        count = logRecur((float) n);
+        System.out.println("对数阶（递归实现）的计算操作数量 = " + count);
+
+        count = linearLogRecur((float) n);
+        System.out.println("线性对数阶（递归实现）的计算操作数量 = " + count);
+
+        count = factorialRecur(n);
+        System.out.println("阶乘阶（递归实现）的计算操作数量 = " + count);
+    }
+}
diff --git a/codes/java/chapter_computational_complexity/time_complexity/worst_best_time_complexity.java b/codes/java/chapter_computational_complexity/time_complexity/worst_best_time_complexity.java
new file mode 100644
index 0000000..d9def6d
--- /dev/null
+++ b/codes/java/chapter_computational_complexity/time_complexity/worst_best_time_complexity.java
@@ -0,0 +1,42 @@
+package chapter_computational_complexity.time_complexity;
+
+import java.util.*;
+
+public class worst_best_time_complexity {
+    /* 生成一个数组，元素为 { 1, 2, ..., n }，顺序被打乱 */
+    static int[] randomNumbers(int n) {
+        Integer[] nums = new Integer[n];
+        // 生成数组 nums = { 1, 2, 3, ..., n }
+        for (int i = 0; i < n; i++) {
+            nums[i] = i + 1;
+        }
+        // 随机打乱数组元素
+        Collections.shuffle(Arrays.asList(nums));
+        // Integer[] -> int[]
+        int[] res = new int[n];
+        for (int i = 0; i < n; i++) {
+            res[i] = nums[i];
+        }
+        return res;
+    }
+
+    /* 查找数组 nums 中数字 1 所在索引 */
+    static int findOne(int[] nums) {
+        for (int i = 0; i < nums.length; i++) {
+            if (nums[i] == 1)
+                return i;
+        }
+        return -1;
+    }
+    
+    /* Driver Code */
+    public static void main(String[] args) {
+        for (int i = 0; i < 10; i++) {
+            int n = 100;
+            int[] nums = randomNumbers(n);
+            int index = findOne(nums);
+            System.out.println("\n数组 [ 1, 2, ..., n ] 被打乱后 = " + Arrays.toString(nums));
+            System.out.println("数字 1 的索引为 " + index);
+        }
+    }
+}
diff --git a/codes/java/include/ListNode.java b/codes/java/include/ListNode.java
new file mode 100755
index 0000000..c8a2283
--- /dev/null
+++ b/codes/java/include/ListNode.java
@@ -0,0 +1,41 @@
+package include;
+
+/**
+ * Definition for a singly-linked list node
+ */
+public class ListNode {
+    public int val;
+    public ListNode next;
+
+    public ListNode(int x) {
+        val = x;
+    }
+    
+    /**
+     * Generate a linked list with an array
+     * @param arr
+     * @return
+     */
+    public static ListNode arrToLinkedList(int[] arr) {
+        ListNode dum = new ListNode(0);
+        ListNode head = dum;
+        for (int val : arr) {
+            head.next = new ListNode(val);
+            head = head.next;
+        }
+        return dum.next;
+    }
+
+    /**
+     * Get a list node with specific value from a linked list
+     * @param head
+     * @param val
+     * @return
+     */
+    public static ListNode getListNode(ListNode head, int val) {
+        while (head != null && head.val != val) {
+            head = head.next;
+        }
+        return head;
+    }
+}
diff --git a/codes/java/include/PrintUtil.java b/codes/java/include/PrintUtil.java
new file mode 100755
index 0000000..ea71591
--- /dev/null
+++ b/codes/java/include/PrintUtil.java
@@ -0,0 +1,88 @@
+package include;
+
+import java.util.*;
+
+class Trunk {
+    Trunk prev;
+    String str;
+
+    Trunk(Trunk prev, String str) {
+        this.prev = prev;
+        this.str = str;
+    }
+};
+
+public class PrintUtil {
+    /**
+     * Print a linked list
+     * @param head
+     */
+    public static void printLinkedList(ListNode head) {
+        List<String> list = new ArrayList<>();
+        while (head != null) {
+            list.add(String.valueOf(head.val));
+            head = head.next;
+        }
+        System.out.println(String.join(" -> ", list));
+    }
+
+    /**
+     * The interface of the tree printer
+     * This tree printer is borrowed from TECHIE DELIGHT
+     * https://www.techiedelight.com/c-program-print-binary-tree/
+     * @param root
+     */
+    public static void printTree(TreeNode root) {
+        printTree(root, null, false);
+    }
+
+    /**
+     * Print a binary tree
+     * @param root
+     * @param prev
+     * @param isLeft
+     */
+    public static void printTree(TreeNode root, Trunk prev, boolean isLeft) {
+        if (root == null) {
+            return;
+        }
+
+        String prev_str = "    ";
+        Trunk trunk = new Trunk(prev, prev_str);
+
+        printTree(root.right, trunk, true);
+
+        if (prev == null) {
+            trunk.str = "———";
+        } else if (isLeft) {
+            trunk.str = "/———";
+            prev_str = "   |";
+        } else {
+            trunk.str = "\\———";
+            prev.str = prev_str;
+        }
+
+        showTrunks(trunk);
+        System.out.println(" " + root.val);
+
+        if (prev != null) {
+            prev.str = prev_str;
+        }
+        trunk.str = "   |";
+
+        printTree(root.left, trunk, false);
+    }
+
+    /**
+     * Helper function to print branches of the binary tree
+     * @param p
+     */
+    public static void showTrunks(Trunk p) {
+        if (p == null) {
+            return;
+        }
+
+        showTrunks(p.prev);
+        System.out.print(p.str);
+    }
+}
diff --git a/codes/java/include/TreeNode.java b/codes/java/include/TreeNode.java
new file mode 100755
index 0000000..e7daebb
--- /dev/null
+++ b/codes/java/include/TreeNode.java
@@ -0,0 +1,80 @@
+package include;
+
+import java.util.*;
+
+/**
+ * Definition for a binary tree node.
+ */
+public class TreeNode {
+    public int val;
+    public TreeNode left;
+    public TreeNode right;
+
+    public TreeNode(int x) {
+        val = x;
+    }
+
+    /**
+     * Generate a binary tree with an array
+     * @param arr
+     * @return
+     */
+    public static TreeNode arrToTree(Integer[] arr) {
+        TreeNode root = new TreeNode(arr[0]);
+        Queue<TreeNode> queue = new LinkedList<>() {{ add(root); }};
+        int i = 1;
+        while(!queue.isEmpty()) {
+            TreeNode node = queue.poll();
+            if(arr[i] != null) {
+                node.left = new TreeNode(arr[i]);
+                queue.add(node.left);
+            }
+            i++;
+            if(arr[i] != null) {
+                node.right = new TreeNode(arr[i]);
+                queue.add(node.right);
+            }
+            i++;
+        }
+        return root;
+    }
+
+    /**
+     * Serialize a binary tree to a list
+     * @param root
+     * @return
+     */
+    public static List<Integer> treeToList(TreeNode root) {
+        List<Integer> list = new ArrayList<>();
+        if(root == null) return list;
+        Queue<TreeNode> queue = new LinkedList<>() {{ add(root); }};
+        while(!queue.isEmpty()) {
+            TreeNode node = queue.poll();
+            if(node != null) {
+                list.add(node.val);
+                queue.add(node.left);
+                queue.add(node.right);
+            }
+            else {
+                list.add(null);
+            }
+        }
+        return list;
+    }
+    
+    /**
+     * Get a tree node with specific value in a binary tree
+     * @param root
+     * @param val
+     * @return
+     */
+    public static TreeNode getTreeNode(TreeNode root, int val) {
+        if (root == null)
+            return null;
+        if (root.val == val)
+            return root;
+        TreeNode left = getTreeNode(root.left, val);
+        TreeNode right = getTreeNode(root.right, val);
+        return left != null ? left : right;
+    }
+}
diff --git a/deploy.sh b/deploy.sh
index f41a0e7..c77fcac 100644
--- a/deploy.sh
+++ b/deploy.sh
@@ -3,5 +3,5 @@ cd site
 git init
 git add -A
 git commit -m 'deploy'
-git push -f git@github.com:krahets/dsa-021.git master:gh-pages
+git push -f git@github.com:krahets/hello-algo.git master:gh-pages
 cd -
diff --git a/docs/index.md b/docs/index.md
index d05ab30..9cc991f 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -1,17 +1,23 @@
 ---
+comments: true
 hide:
   - footer
 ---
 
-# Data Structure And Algorithm: From 0 to 1
+# Hello，算法！
 
-## Update Log
+TODO
 
-To be updated...
+## 更新日志
 
-| Chapter      | Date       |
+| 更新内容    | 日期     |
 | ------------ | ---------- |
-| 数组与链表     | 2022-10-15 |
-| 数据结构简介   | 2022-10-20 |
-| 前言          | 2022-10-23 |
-| 计算复杂度     | 2022-11-03 |
+| 新增：算法无处不在  | 2022-10-10 |
+| 新增：数组与链表   | 2022-10-15 |
+| 新增：数据结构简介 | 2022-10-20 |
+| 新增：前言         | 2022-10-23 |
+| 新增：计算复杂度   | 2022-11-03 |
+| 更新：配图 | 2022-11-04 |
+| 新增：数据与内存 | 2022-11-05 |
+| 更新：各章节 Java 代码 | 2022-11-06 |
+| 更新：列表 Java 代码、配图 | 2022-11-07 |
diff --git a/mkdocs.yml b/mkdocs.yml
index fcd06d7..e79aede 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -1,11 +1,11 @@
 # Project information
-site_name: 算法入门速成
-site_url: https://krahets.github.io/dsa-021/
+site_name: Hello 算法
+site_url: https://krahets.github.io/hello-algo/
 site_author: Krahets
 site_description: Your first book to learn Data Structure And Algorithm.
 # Repository
-repo_name: krahets/dsa-021
-repo_url: https://github.com/krahets/dsa-021
+repo_name: krahets/hello-algo
+repo_url: https://github.com/krahets/hello-algo
 
 # Copyright
 copyright: Copyright &copy; 2020 - 2022 Krahets
@@ -115,17 +115,18 @@ extra_css:
 nav:
   - 关于本书:
     - chapter_about/index.md
-  - 前言: 
+  - 算法无处不在: 
     - chapter_introduction/index.md
   - 计算复杂度:
     - chapter_computational_complexity/index.md
     - 算法效率评估: chapter_computational_complexity/performance_evaluation.md
     - 时间复杂度: chapter_computational_complexity/time_complexity.md
     - 空间复杂度: chapter_computational_complexity/space_complexity.md
+    - 权衡时间与空间: chapter_computational_complexity/space_time_tradeoff.md
     - 小结: chapter_computational_complexity/summary.md
   - 数据结构简介: 
     - chapter_data_structure/index.md
-    - 数据与内存: chapter_data_structure/computer_memory.md
+    - 数据与内存: chapter_data_structure/data_and_memory.md
     - 数据结构分类: chapter_data_structure/classification_of_data_strcuture.md
     - 小结: chapter_data_structure/summary.md
   - 数组与链表: 
@@ -133,4 +134,6 @@ nav:
     - 数组: chapter_array_and_linkedlist/array.md
     - 链表: chapter_array_and_linkedlist/linked_list.md
     - 列表: chapter_array_and_linkedlist/list.md
-    - 小结: chapter_array_and_linkedlist/summary.md
\ No newline at end of file
+    - 小结: chapter_array_and_linkedlist/summary.md
+  - License:
+    - chapter_license/index.md
\ No newline at end of file