feat: add Merge Two Sorted Lists in Racket

dukeluo · dukeluo · commit 8e7139e7d259 · 2023-09-19T22:51:26.000+08:00
diff --git a/README.md b/README.md
@@ -4,40 +4,40 @@ https://neetcode.io/roadmap
 
 ### NeetCode
 
-| #   | Title                                                                                                                           | Difficulty | Solution                                                                                  | Category         |
-| --- | ------------------------------------------------------------------------------------------------------------------------------- | ---------- | ----------------------------------------------------------------------------------------- | ---------------- |
-| 217 | [Contains Duplicate](https://leetcode.com/problems/contains-duplicate/)                                                         | Easy       | [ts](./TypeScript/217.contains-duplicate.ts)                                              | Arrays & Hashing |
-| 242 | [Valid Anagram](https://leetcode.com/problems/valid-anagram/)                                                                   | Easy       | [ts](./TypeScript/242.valid-anagram.ts)                                                   | Arrays & Hashing |
-| 242 | [Two Sum](https://leetcode.com/problems/two-sum/)                                                                               | Easy       | [ts](./TypeScript/1.two-sum.ts)                                                           | Arrays & Hashing |
-| 49  | [Group Anagrams](https://leetcode.com/problems/two-sum/)                                                                        | Medium     | [ts](./TypeScript/49.group-anagrams.ts)                                                   | Arrays & Hashing |
-| 347 | [Top K Frequent Elements](https://leetcode.com/problems/top-k-frequent-elements/)                                               | Medium     | [ts](./TypeScript/347.top-k-frequent-elements.ts)                                         | Arrays & Hashing |
-| 238 | [Product of Array Except Self](https://leetcode.com/problems/product-of-array-except-self/)                                     | Medium     | [ts](./TypeScript/238.product-of-array-except-self.ts)                                    | Arrays & Hashing |
-| 36  | [Valid Sudoku](https://leetcode.com/problems/valid-sudoku/)                                                                     | Medium     | [ts](./TypeScript/36.valid-sudoku.ts)                                                     | Arrays & Hashing |
-| 659 | [Encode and Decode Strings](https://www.lintcode.com/problem/659/)                                                              | Medium     | [ts](./TypeScript/659.encode-and-decode-strings.ts)                                       | Arrays & Hashing |
-| 128 | [Longest Consecutive Sequence](https://leetcode.com/problems/longest-consecutive-sequence/)                                     | Medium     | [ts](./TypeScript/128.longest-consecutive-sequence.ts)                                    | Arrays & Hashing |
-| 125 | [Valid Palindrome](https://leetcode.com/problems/valid-palindrome/)                                                             | Easy       | [ts](./TypeScript/125.valid-palindrome.ts)                                                | Two Pointers     |
-| 167 | [Two Sum II - Input Array Is Sorted](https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/)                           | Medium     | [ts](./TypeScript/167.two-sum-ii-input-array-is-sorted.ts)                                | Two Pointers     |
-| 15  | [3Sum](https://leetcode.com/problems/3sum/)                                                                                     | Medium     | [ts](./TypeScript/15.3sum.ts)                                                             | Two Pointers     |
-| 11  | [Container With Most Water](https://leetcode.com/problems/container-with-most-water/)                                           | Medium     | [ts](./TypeScript/11.container-with-most-water.ts)                                        | Two Pointers     |
-| 42  | [Trapping Rain Water](https://leetcode.com/problems/trapping-rain-water/)                                                       | Hard       | [ts](./TypeScript/42.trapping-rain-water.ts)                                              | Two Pointers     |
-| 20  | [Valid Parentheses](https://leetcode.com/problems/valid-parentheses/)                                                           | Easy       | [ts](./TypeScript/20.valid-parentheses.ts)                                                | Stack            |
-| 155 | [Min Stack](https://leetcode.com/problems/min-stack/)                                                                           | Medium     | [ts](./TypeScript/155.min-stack.ts)                                                       | Stack            |
-| 150 | [Evaluate Reverse Polish Notation](https://leetcode.com/problems/evaluate-reverse-polish-notation/)                             | Medium     | [ts](./TypeScript/150.evaluate-reverse-polish-notation.ts)                                | Stack            |
-| 22  | [Generate Parentheses](https://leetcode.com/problems/generate-parentheses/)                                                     | Medium     | [ts](./TypeScript/22.generate-parentheses.ts)                                             | Stack            |
-| 739 | [Daily Temperatures](https://leetcode.com/problems/daily-temperatures/)                                                         | Medium     | [ts](./TypeScript/739.daily-temperatures.ts)                                              | Stack            |
-| 853 | [Car Fleet](https://leetcode.com/problems/car-fleet/)                                                                           | Medium     | [ts](./TypeScript/853.car-fleet.ts)                                                       | Stack            |
-| 84  | [Largest Rectangle in Histogram](https://leetcode.com/problems/largest-rectangle-in-histogram/)                                 | Hard       | [ts](./TypeScript/84.largest-rectangle-in-histogram.ts)                                   | Stack            |
-| 704 | [Binary Search](https://leetcode.com/problems/binary-search/)                                                                   | Easy       | [ts](./TypeScript/704.binary-search.ts)                                                   | Binary Search    |
-| 74  | [Search a 2D Matrix](https://leetcode.com/problems/search-a-2d-matrix/)                                                         | Medium     | [ts](./TypeScript/74.search-a-2d-matrix.ts)                                               | Binary Search    |
-| 875 | [Koko Eating Bananas](https://leetcode.com/problems/koko-eating-bananas/)                                                       | Medium     | [ts](./TypeScript/875.koko-eating-bananas.ts)                                             | Binary Search    |
-| 153 | [Find Minimum in Rotated Sorted Array](https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/)                     | Medium     | [ts](./TypeScript/153.find-minimum-in-rotated-sorted-array.ts)                            | Binary Search    |
-| 33  | [Search in Rotated Sorted Array](https://leetcode.com/problems/search-in-rotated-sorted-array/)                                 | Medium     | [ts](./TypeScript/33.search-in-rotated-sorted-array.ts)                                   | Binary Search    |
-| 981 | [Time Based Key-Value Store](https://leetcode.com/problems/time-based-key-value-store/)                                         | Medium     | [ts](./TypeScript/981.time-based-key-value-store.ts)                                      | Binary Search    |
-| 121 | [Best Time to Buy and Sell Stock](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/)                               | Easy       | [ts](./TypeScript/121.best-time-to-buy-and-sell-stock.ts)                                 | Sliding Window   |
-| 3   | [Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/) | Medium     | [ts](./TypeScript/3.longest-substring-without-repeating-characters.ts)                    | Sliding Window   |
-| 424 | [Longest Repeating Character Replacement](https://leetcode.com/problems/longest-repeating-character-replacement/)               | Medium     | [ts](./TypeScript/424.longest-repeating-character-replacement.ts)                         | Sliding Window   |
-| 206 | [Reverse Linked List](https://leetcode.com/problems/reverse-linked-list/)                                                       | Easy       | [ts](./TypeScript/206.reverse-linked-list.ts) [rkt](./Racket/206.reverse-linked-list.rkt) | Linked List      |
-| 21  | [Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/)                                                 | Easy       | [ts](./TypeScript/21.merge-two-sorted-lists.ts)                                           | Linked List      |
+| #   | Title                                                                                                                           | Difficulty | Solution                                                                                      | Category         |
+| --- | ------------------------------------------------------------------------------------------------------------------------------- | ---------- | --------------------------------------------------------------------------------------------- | ---------------- |
+| 217 | [Contains Duplicate](https://leetcode.com/problems/contains-duplicate/)                                                         | Easy       | [ts](./TypeScript/217.contains-duplicate.ts)                                                  | Arrays & Hashing |
+| 242 | [Valid Anagram](https://leetcode.com/problems/valid-anagram/)                                                                   | Easy       | [ts](./TypeScript/242.valid-anagram.ts)                                                       | Arrays & Hashing |
+| 242 | [Two Sum](https://leetcode.com/problems/two-sum/)                                                                               | Easy       | [ts](./TypeScript/1.two-sum.ts)                                                               | Arrays & Hashing |
+| 49  | [Group Anagrams](https://leetcode.com/problems/two-sum/)                                                                        | Medium     | [ts](./TypeScript/49.group-anagrams.ts)                                                       | Arrays & Hashing |
+| 347 | [Top K Frequent Elements](https://leetcode.com/problems/top-k-frequent-elements/)                                               | Medium     | [ts](./TypeScript/347.top-k-frequent-elements.ts)                                             | Arrays & Hashing |
+| 238 | [Product of Array Except Self](https://leetcode.com/problems/product-of-array-except-self/)                                     | Medium     | [ts](./TypeScript/238.product-of-array-except-self.ts)                                        | Arrays & Hashing |
+| 36  | [Valid Sudoku](https://leetcode.com/problems/valid-sudoku/)                                                                     | Medium     | [ts](./TypeScript/36.valid-sudoku.ts)                                                         | Arrays & Hashing |
+| 659 | [Encode and Decode Strings](https://www.lintcode.com/problem/659/)                                                              | Medium     | [ts](./TypeScript/659.encode-and-decode-strings.ts)                                           | Arrays & Hashing |
+| 128 | [Longest Consecutive Sequence](https://leetcode.com/problems/longest-consecutive-sequence/)                                     | Medium     | [ts](./TypeScript/128.longest-consecutive-sequence.ts)                                        | Arrays & Hashing |
+| 125 | [Valid Palindrome](https://leetcode.com/problems/valid-palindrome/)                                                             | Easy       | [ts](./TypeScript/125.valid-palindrome.ts)                                                    | Two Pointers     |
+| 167 | [Two Sum II - Input Array Is Sorted](https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/)                           | Medium     | [ts](./TypeScript/167.two-sum-ii-input-array-is-sorted.ts)                                    | Two Pointers     |
+| 15  | [3Sum](https://leetcode.com/problems/3sum/)                                                                                     | Medium     | [ts](./TypeScript/15.3sum.ts)                                                                 | Two Pointers     |
+| 11  | [Container With Most Water](https://leetcode.com/problems/container-with-most-water/)                                           | Medium     | [ts](./TypeScript/11.container-with-most-water.ts)                                            | Two Pointers     |
+| 42  | [Trapping Rain Water](https://leetcode.com/problems/trapping-rain-water/)                                                       | Hard       | [ts](./TypeScript/42.trapping-rain-water.ts)                                                  | Two Pointers     |
+| 20  | [Valid Parentheses](https://leetcode.com/problems/valid-parentheses/)                                                           | Easy       | [ts](./TypeScript/20.valid-parentheses.ts)                                                    | Stack            |
+| 155 | [Min Stack](https://leetcode.com/problems/min-stack/)                                                                           | Medium     | [ts](./TypeScript/155.min-stack.ts)                                                           | Stack            |
+| 150 | [Evaluate Reverse Polish Notation](https://leetcode.com/problems/evaluate-reverse-polish-notation/)                             | Medium     | [ts](./TypeScript/150.evaluate-reverse-polish-notation.ts)                                    | Stack            |
+| 22  | [Generate Parentheses](https://leetcode.com/problems/generate-parentheses/)                                                     | Medium     | [ts](./TypeScript/22.generate-parentheses.ts)                                                 | Stack            |
+| 739 | [Daily Temperatures](https://leetcode.com/problems/daily-temperatures/)                                                         | Medium     | [ts](./TypeScript/739.daily-temperatures.ts)                                                  | Stack            |
+| 853 | [Car Fleet](https://leetcode.com/problems/car-fleet/)                                                                           | Medium     | [ts](./TypeScript/853.car-fleet.ts)                                                           | Stack            |
+| 84  | [Largest Rectangle in Histogram](https://leetcode.com/problems/largest-rectangle-in-histogram/)                                 | Hard       | [ts](./TypeScript/84.largest-rectangle-in-histogram.ts)                                       | Stack            |
+| 704 | [Binary Search](https://leetcode.com/problems/binary-search/)                                                                   | Easy       | [ts](./TypeScript/704.binary-search.ts)                                                       | Binary Search    |
+| 74  | [Search a 2D Matrix](https://leetcode.com/problems/search-a-2d-matrix/)                                                         | Medium     | [ts](./TypeScript/74.search-a-2d-matrix.ts)                                                   | Binary Search    |
+| 875 | [Koko Eating Bananas](https://leetcode.com/problems/koko-eating-bananas/)                                                       | Medium     | [ts](./TypeScript/875.koko-eating-bananas.ts)                                                 | Binary Search    |
+| 153 | [Find Minimum in Rotated Sorted Array](https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/)                     | Medium     | [ts](./TypeScript/153.find-minimum-in-rotated-sorted-array.ts)                                | Binary Search    |
+| 33  | [Search in Rotated Sorted Array](https://leetcode.com/problems/search-in-rotated-sorted-array/)                                 | Medium     | [ts](./TypeScript/33.search-in-rotated-sorted-array.ts)                                       | Binary Search    |
+| 981 | [Time Based Key-Value Store](https://leetcode.com/problems/time-based-key-value-store/)                                         | Medium     | [ts](./TypeScript/981.time-based-key-value-store.ts)                                          | Binary Search    |
+| 121 | [Best Time to Buy and Sell Stock](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/)                               | Easy       | [ts](./TypeScript/121.best-time-to-buy-and-sell-stock.ts)                                     | Sliding Window   |
+| 3   | [Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/) | Medium     | [ts](./TypeScript/3.longest-substring-without-repeating-characters.ts)                        | Sliding Window   |
+| 424 | [Longest Repeating Character Replacement](https://leetcode.com/problems/longest-repeating-character-replacement/)               | Medium     | [ts](./TypeScript/424.longest-repeating-character-replacement.ts)                             | Sliding Window   |
+| 206 | [Reverse Linked List](https://leetcode.com/problems/reverse-linked-list/)                                                       | Easy       | [ts](./TypeScript/206.reverse-linked-list.ts) [rkt](./Racket/206.reverse-linked-list.rkt)     | Linked List      |
+| 21  | [Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/)                                                 | Easy       | [ts](./TypeScript/21.merge-two-sorted-lists.ts) [rkt](./Racket/21.merge-two-sorted-lists.rkt) | Linked List      |
 
 ### Others
 
diff --git a/Racket/21.merge-two-sorted-lists.rkt b/Racket/21.merge-two-sorted-lists.rkt
@@ -0,0 +1,15 @@
+#lang racket
+
+(struct list-node
+  (val next) #:mutable #:transparent)
+
+(define (make-list-node [val 0])
+  (list-node val #f))
+
+
+(define/contract (merge-two-lists list1 list2)
+  (-> (or/c list-node? #f) (or/c list-node? #f) (or/c list-node? #f))
+  (cond ((false? list1) list2)
+        ((false? list2) list1)
+        ((< (list-node-val list1) (list-node-val list2)) (list-node (list-node-val list1) (merge-two-lists (list-node-next list1) list2)))
+        (else (list-node (list-node-val list2) (merge-two-lists list1 (list-node-next list2))))))
