Added tasks 21-25

Author: ThanhNIT

README.md

@@ -77,6 +77,7 @@ JavaScript-based LeetCode algorithm problem solutions, regularly updated.
 
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+| 0021 |[Merge Two Sorted Lists](src/main/js/g0001_0100/s0021_merge_two_sorted_lists/solution.js)| Easy | Top_100_Liked_Questions, Top_Interview_Questions, Linked_List, Recursion, Big_O_Time_O(m+n)_Space_O(m+n) | 0 | 100.00
 
 #### Day 11 Recursion Backtracking
 
@@ -157,6 +158,7 @@ JavaScript-based LeetCode algorithm problem solutions, regularly updated.
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 | 0017 |[Letter Combinations of a Phone Number](src/main/js/g0001_0100/s0017_letter_combinations_of_a_phone_number/solution.js)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Backtracking, Big_O_Time_O(4^n)_Space_O(n) | 0 | 100.00
+| 0022 |[Generate Parentheses](src/main/js/g0001_0100/s0022_generate_parentheses/solution.js)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, String, Dynamic_Programming, Backtracking, Big_O_Time_O(2^n)_Space_O(n) | 0 | 100.00
 
 #### Day 12 Dynamic Programming
 
@@ -786,6 +788,7 @@ JavaScript-based LeetCode algorithm problem solutions, regularly updated.
 
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+| 0021 |[Merge Two Sorted Lists](src/main/js/g0001_0100/s0021_merge_two_sorted_lists/solution.js)| Easy | Top_100_Liked_Questions, Top_Interview_Questions, Linked_List, Recursion, Big_O_Time_O(m+n)_Space_O(m+n) | 0 | 100.00
 
 #### Day 4 Linked List
 
@@ -1005,6 +1008,9 @@ JavaScript-based LeetCode algorithm problem solutions, regularly updated.
 
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+| 0024 |[Swap Nodes in Pairs](src/main/js/g0001_0100/s0024_swap_nodes_in_pairs/solution.js)| Medium | Top_100_Liked_Questions, Linked_List, Recursion, Big_O_Time_O(n)_Space_O(1) | 1 | 100.00
+| 0021 |[Merge Two Sorted Lists](src/main/js/g0001_0100/s0021_merge_two_sorted_lists/solution.js)| Easy | Top_100_Liked_Questions, Top_Interview_Questions, Linked_List, Recursion, Big_O_Time_O(m+n)_Space_O(m+n) | 0 | 100.00
+| 0025 |[Reverse Nodes in k-Group](src/main/js/g0001_0100/s0025_reverse_nodes_in_k_group/solution.js)| Hard | Top_100_Liked_Questions, Linked_List, Recursion, Big_O_Time_O(n)_Space_O(k) | 0 | 100.00
 
 #### Udemy Tree Stack Queue
 
@@ -1031,6 +1037,7 @@ JavaScript-based LeetCode algorithm problem solutions, regularly updated.
 
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+| 0022 |[Generate Parentheses](src/main/js/g0001_0100/s0022_generate_parentheses/solution.js)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, String, Dynamic_Programming, Backtracking, Big_O_Time_O(2^n)_Space_O(n) | 0 | 100.00
 | 0017 |[Letter Combinations of a Phone Number](src/main/js/g0001_0100/s0017_letter_combinations_of_a_phone_number/solution.js)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Backtracking, Big_O_Time_O(4^n)_Space_O(n) | 0 | 100.00
 
 #### Udemy Bit Manipulation
@@ -1080,6 +1087,7 @@ JavaScript-based LeetCode algorithm problem solutions, regularly updated.
 
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+| 0021 |[Merge Two Sorted Lists](src/main/js/g0001_0100/s0021_merge_two_sorted_lists/solution.js)| Easy | Top_100_Liked_Questions, Top_Interview_Questions, Linked_List, Recursion, Big_O_Time_O(m+n)_Space_O(m+n) | 0 | 100.00
 
 #### Day 8 Linked List
 
@@ -1181,11 +1189,13 @@ JavaScript-based LeetCode algorithm problem solutions, regularly updated.
 
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+| 0024 |[Swap Nodes in Pairs](src/main/js/g0001_0100/s0024_swap_nodes_in_pairs/solution.js)| Medium | Top_100_Liked_Questions, Linked_List, Recursion, Big_O_Time_O(n)_Space_O(1) | 1 | 100.00
 
 #### Day 13 Linked List
 
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+| 0025 |[Reverse Nodes in k-Group](src/main/js/g0001_0100/s0025_reverse_nodes_in_k_group/solution.js)| Hard | Top_100_Liked_Questions, Linked_List, Recursion, Big_O_Time_O(n)_Space_O(k) | 0 | 100.00
 
 #### Day 14 Stack Queue
 
@@ -1231,6 +1241,11 @@ JavaScript-based LeetCode algorithm problem solutions, regularly updated.
 
 | #    |      Title     | Difficulty  | Tag         | Time, ms | Time, %
 |------|----------------|-------------|-------------|----------|---------
+| 0025 |[Reverse Nodes in k-Group](src/main/js/g0001_0100/s0025_reverse_nodes_in_k_group/solution.js)| Hard | Top_100_Liked_Questions, Linked_List, Recursion, Data_Structure_II_Day_13_Linked_List, Udemy_Linked_List, Big_O_Time_O(n)_Space_O(k) | 0 | 100.00
+| 0024 |[Swap Nodes in Pairs](src/main/js/g0001_0100/s0024_swap_nodes_in_pairs/solution.js)| Medium | Top_100_Liked_Questions, Linked_List, Recursion, Data_Structure_II_Day_12_Linked_List, Udemy_Linked_List, Big_O_Time_O(n)_Space_O(1) | 1 | 100.00
+| 0023 |[Merge k Sorted Lists](src/main/js/g0001_0100/s0023_merge_k_sorted_lists/solution.js)| Hard | Top_100_Liked_Questions, Top_Interview_Questions, Heap_Priority_Queue, Linked_List, Divide_and_Conquer, Merge_Sort, Big_O_Time_O(k\*n\*log(k))_Space_O(log(k)) | 3 | 99.39
+| 0022 |[Generate Parentheses](src/main/js/g0001_0100/s0022_generate_parentheses/solution.js)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, String, Dynamic_Programming, Backtracking, Algorithm_II_Day_11_Recursion_Backtracking, Udemy_Backtracking/Recursion, Big_O_Time_O(2^n)_Space_O(n) | 0 | 100.00
+| 0021 |[Merge Two Sorted Lists](src/main/js/g0001_0100/s0021_merge_two_sorted_lists/solution.js)| Easy | Top_100_Liked_Questions, Top_Interview_Questions, Linked_List, Recursion, Data_Structure_I_Day_7_Linked_List, Algorithm_I_Day_10_Recursion_Backtracking, Level_1_Day_3_Linked_List, Udemy_Linked_List, Big_O_Time_O(m+n)_Space_O(m+n) | 0 | 100.00
 | 0020 |[Valid Parentheses](src/main/js/g0001_0100/s0020_valid_parentheses/solution.js)| Easy | Top_100_Liked_Questions, Top_Interview_Questions, String, Stack, Data_Structure_I_Day_9_Stack_Queue, Udemy_Strings, Big_O_Time_O(n)_Space_O(n) | 0 | 100.00
 | 0019 |[Remove Nth Node From End of List](src/main/js/g0001_0100/s0019_remove_nth_node_from_end_of_list/solution.js)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Two_Pointers, Linked_List, Algorithm_I_Day_5_Two_Pointers, Level_2_Day_3_Linked_List, Big_O_Time_O(L)_Space_O(L) | 0 | 100.00
 | 0017 |[Letter Combinations of a Phone Number](src/main/js/g0001_0100/s0017_letter_combinations_of_a_phone_number/solution.js)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Backtracking, Algorithm_II_Day_11_Recursion_Backtracking, Udemy_Backtracking/Recursion, Big_O_Time_O(4^n)_Space_O(n) | 0 | 100.00

src/main/js/g0001_0100/s0021_merge_two_sorted_lists/readme.md

@@ -0,0 +1,31 @@
+21\. Merge Two Sorted Lists
+
+Easy
+
+Merge two sorted linked lists and return it as a **sorted** list. The list should be made by splicing together the nodes of the first two lists.
+
+**Example 1:**
+
+![](https://assets.leetcode.com/uploads/2020/10/03/merge_ex1.jpg)
+
+**Input:** l1 = [1,2,4], l2 = [1,3,4]
+
+**Output:** [1,1,2,3,4,4]
+
+**Example 2:**
+
+**Input:** l1 = [], l2 = []
+
+**Output:** []
+
+**Example 3:**
+
+**Input:** l1 = [], l2 = [0]
+
+**Output:** [0]
+
+**Constraints:**
+
+*   The number of nodes in both lists is in the range `[0, 50]`.
+*   `-100 <= Node.val <= 100`
+*   Both `l1` and `l2` are sorted in **non-decreasing** order.

src/main/js/g0001_0100/s0021_merge_two_sorted_lists/solution.js

@@ -0,0 +1,41 @@
+// #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Linked_List #Recursion
+// #Data_Structure_I_Day_7_Linked_List #Algorithm_I_Day_10_Recursion_Backtracking
+// #Level_1_Day_3_Linked_List #Udemy_Linked_List #Big_O_Time_O(m+n)_Space_O(m+n)
+// #2024_12_04_Time_0_ms_(100.00%)_Space_52.3_MB_(20.64%)
+
+import { ListNode } from "../../com_github_leetcode/listnode";
+
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val, next) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.next = (next===undefined ? null : next)
+ * }
+ */
+/**
+ * @param {ListNode} list1
+ * @param {ListNode} list2
+ * @return {ListNode}
+ */
+var mergeTwoLists = function (list1, list2) {
+    let dummy = new ListNode()
+    let current = dummy
+    while (list1 !== null && list2 !== null) {
+        if (list1.val <= list2.val) {
+            current.next = list1
+            list1 = list1.next
+        } else {
+            current.next = list2
+            list2 = list2.next
+        }
+        current = current.next
+    }
+    if (list1 !== null) {
+        current.next = list1
+    } else if (list2 !== null) {
+        current.next = list2
+    }
+    return dummy.next;
+};
+
+export { mergeTwoLists }

src/main/js/g0001_0100/s0022_generate_parentheses/readme.md

@@ -0,0 +1,21 @@
+22\. Generate Parentheses
+
+Medium
+
+Given `n` pairs of parentheses, write a function to _generate all combinations of well-formed parentheses_.
+
+**Example 1:**
+
+**Input:** n = 3
+
+**Output:** ["((()))","(()())","(())()","()(())","()()()"]
+
+**Example 2:**
+
+**Input:** n = 1
+
+**Output:** ["()"]
+
+**Constraints:**
+
+*   `1 <= n <= 8`

src/main/js/g0001_0100/s0022_generate_parentheses/solution.js

@@ -0,0 +1,29 @@
+// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #String #Dynamic_Programming
+// #Backtracking #Algorithm_II_Day_11_Recursion_Backtracking #Udemy_Backtracking/Recursion
+// #Big_O_Time_O(2^n)_Space_O(n) #2024_12_04_Time_0_ms_(100.00%)_Space_50.7_MB_(42.00%)
+
+/**
+ * @param {number} n
+ * @return {string[]}
+ */
+var generateParenthesis = function(n) {
+    const result = [];
+    
+    const generate = (current, open, close) => {
+        if (open === 0 && close === 0) {
+            result.push(current);
+            return;
+        }
+        if (open > 0) {
+            generate(current + '(', open - 1, close);
+        }
+        if (close > 0 && open < close) {
+            generate(current + ')', open, close - 1);
+        }
+    };
+
+    generate('', n, n);
+    return result;
+};
+
+export { generateParenthesis }

src/main/js/g0001_0100/s0023_merge_k_sorted_lists/readme.md

@@ -0,0 +1,36 @@
+23\. Merge k Sorted Lists
+
+Hard
+
+You are given an array of `k` linked-lists `lists`, each linked-list is sorted in ascending order.
+
+_Merge all the linked-lists into one sorted linked-list and return it._
+
+**Example 1:**
+
+**Input:** lists = [[1,4,5],[1,3,4],[2,6]]
+
+**Output:** [1,1,2,3,4,4,5,6]
+
+**Explanation:** The linked-lists are: [ 1->4->5, 1->3->4, 2->6 ] merging them into one sorted list: 1->1->2->3->4->4->5->6
+
+**Example 2:**
+
+**Input:** lists = []
+
+**Output:** []
+
+**Example 3:**
+
+**Input:** lists = [[]]
+
+**Output:** []
+
+**Constraints:**
+
+*   `k == lists.length`
+*   `0 <= k <= 10^4`
+*   `0 <= lists[i].length <= 500`
+*   `-10^4 <= lists[i][j] <= 10^4`
+*   `lists[i]` is sorted in **ascending order**.
+*   The sum of `lists[i].length` won't exceed `10^4`.

src/main/js/g0001_0100/s0023_merge_k_sorted_lists/solution.js

@@ -0,0 +1,74 @@
+// #Hard #Top_100_Liked_Questions #Top_Interview_Questions #Heap_Priority_Queue #Linked_List
+// #Divide_and_Conquer #Merge_Sort #Big_O_Time_O(k*n*log(k))_Space_O(log(k))
+// #2024_12_04_Time_3_ms_(99.39%)_Space_55.8_MB_(67.69%)
+
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val, next) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.next = (next===undefined ? null : next)
+ * }
+ */
+/**
+ * @param {ListNode[]} lists
+ * @return {ListNode}
+ */
+const mergeKLists = function(lists) {
+    if (lists.length === 0) {
+        return null
+    }
+    return mergeKListsHelper(lists, 0, lists.length)
+};
+
+const mergeKListsHelper = function(lists, leftIndex, rightIndex) {
+    if (rightIndex > leftIndex + 1) {
+        const mid = Math.floor((leftIndex + rightIndex) / 2)
+        const left = mergeKListsHelper(lists, leftIndex, mid)
+        const right = mergeKListsHelper(lists, mid, rightIndex)
+        return mergeTwoLists(left, right)
+    } else {
+        return lists[leftIndex]
+    }
+};
+
+const mergeTwoLists = function(left, right) {
+    if (left === null) {
+        return right
+    }
+    if (right === null) {
+        return left
+    }
+
+    let res;
+    if (left.val <= right.val) {
+        res = left
+        left = left.next
+    } else {
+        res = right
+        right = right.next
+    }
+
+    let current = res;
+    while (left !== null || right !== null) {
+        if (left === null) {
+            current.next = right
+            right = right.next
+        } else if (right === null) {
+            current.next = left
+            left = left.next
+        } else {
+            if (left.val <= right.val) {
+                current.next = left
+                left = left.next
+            } else {
+                current.next = right
+                right = right.next
+            }
+        }
+        current = current.next
+    }
+
+    return res
+};
+
+export { mergeKLists }

src/main/js/g0001_0100/s0024_swap_nodes_in_pairs/readme.md

@@ -0,0 +1,30 @@
+24\. Swap Nodes in Pairs
+
+Medium
+
+Given a linked list, swap every two adjacent nodes and return its head. You must solve the problem without modifying the values in the list's nodes (i.e., only nodes themselves may be changed.)
+
+**Example 1:**
+
+![](https://assets.leetcode.com/uploads/2020/10/03/swap_ex1.jpg)
+
+**Input:** head = [1,2,3,4]
+
+**Output:** [2,1,4,3]
+
+**Example 2:**
+
+**Input:** head = []
+
+**Output:** []
+
+**Example 3:**
+
+**Input:** head = [1]
+
+**Output:** [1]
+
+**Constraints:**
+
+*   The number of nodes in the list is in the range `[0, 100]`.
+*   `0 <= Node.val <= 100`

src/main/js/g0001_0100/s0024_swap_nodes_in_pairs/solution.js

@@ -0,0 +1,54 @@
+// #Medium #Top_100_Liked_Questions #Linked_List #Recursion #Data_Structure_II_Day_12_Linked_List
+// #Udemy_Linked_List #Big_O_Time_O(n)_Space_O(1)
+// #2024_12_04_Time_1_ms_(100.00%)_Space_49.6_MB_(8.69%)
+
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val, next) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.next = (next===undefined ? null : next)
+ * }
+ */
+/**
+ * @param {ListNode} head
+ * @return {ListNode}
+ */
+const swapPairs = function (head) {
+    if (head === null) {
+        return null
+    }
+
+    const getLength = (node) => {
+        let count = 0
+        while (node !== null) {
+            count++
+            node = node.next
+        }
+        return count
+    };
+
+    const reverse = (node, length) => {
+        if (length < 2) {
+            return node
+        }
+
+        let current = node
+        let prev = null
+        let next
+
+        for (let i = 0; i < 2; i++) {
+            next = current.next
+            current.next = prev
+            prev = current
+            current = next
+        }
+
+        node.next = reverse(current, length - 2)
+        return prev
+    };
+
+    const len = getLength(head)
+    return reverse(head, len)
+};
+
+export { swapPairs }