feat: populate note files with problem descriptions and code stubs

Add populate-notes.mjs that fetches problem descriptions and
Python/C++ code stubs from LeetCode's GraphQL API. Populated
all 197 NeetCode 150 note files with:
- Problem description (examples, constraints)
- Python code stub (function signature)
- C++ code stub (function signature + includes)

API responses cached in leetcode/.cache/leetcode/ for instant re-runs.

org/study_deck_02/dsa/tries/0208-implement-trie-prefix-tree.org

@@ -1,18 +1,103 @@
 #+PROPERTY: STUDY_DECK_02
 * TODO 0208. Implement Trie Prefix Tree :medium:
 :PROPERTIES:
-:NEETCODE: [[file:../../roadmap.org::*0208. Implement Trie Prefix Tree][Roadmap]]
+:NEETCODE: [[file:../../roadmap.org::*0208. Implement Trie Prefix Tree][0208. Implement Trie Prefix Tree]]
 :END:
 
+A *trie* (pronounced as "try") or *prefix tree* is a tree data structure used to efficiently store and retrieve keys in a dataset of strings. There are various applications of this data structure, such as autocomplete and spellchecker.
+
+Implement the Trie class:
+
+ - ~Trie()~ Initializes the trie object.
+
+ - ~void insert(String word)~ Inserts the string ~word~ into the trie.
+
+ - ~boolean search(String word)~ Returns ~true~ if the string ~word~ is in the trie (i.e., was inserted before), and ~false~ otherwise.
+
+ - ~boolean startsWith(String prefix)~ Returns ~true~ if there is a previously inserted string ~word~ that has the prefix ~prefix~, and ~false~ otherwise.
+
+*Example 1:*
+
+
+#+begin_src
+Input
+["Trie", "insert", "search", "search", "startsWith", "insert", "search"]
+[[], ["apple"], ["apple"], ["app"], ["app"], ["app"], ["app"]]
+Output
+[null, null, true, false, true, null, true]
+
+Explanation
+Trie trie = new Trie();
+trie.insert("apple");
+trie.search("apple");   // return True
+trie.search("app");     // return False
+trie.startsWith("app"); // return True
+trie.insert("app");
+trie.search("app");     // return True
+#+end_src
+
+
+*Constraints:*
+
+ - ~1 <= word.length, prefix.length <= 2000~
+
+ - ~word~ and ~prefix~ consist only of lowercase English letters.
+
+ - At most ~3 * 10^{4}~ calls *in total* will be made to ~insert~, ~search~, and ~startsWith~.
+
 ** TODO Approach
 Write your approach here.
 
 ** TODO Python
 #+begin_src python
+class Trie:
 
+    def __init__(self):
+        
+
+    def insert(self, word: str) -> None:
+        
+
+    def search(self, word: str) -> bool:
+        
+
+    def startsWith(self, prefix: str) -> bool:
+        
+
+
+# Your Trie object will be instantiated and called as such:
+# obj = Trie()
+# obj.insert(word)
+# param_2 = obj.search(word)
+# param_3 = obj.startsWith(prefix)
 #+end_src
 
 ** TODO C++
 #+begin_src cpp
+class Trie {
+public:
+    Trie() {
+        
+    }
+    
+    void insert(string word) {
+        
+    }
+    
+    bool search(string word) {
+        
+    }
+    
+    bool startsWith(string prefix) {
+        
+    }
+};
 
+/**
+ * Your Trie object will be instantiated and called as such:
+ * Trie* obj = new Trie();
+ * obj->insert(word);
+ * bool param_2 = obj->search(word);
+ * bool param_3 = obj->startsWith(prefix);
+ */
 #+end_src

org/study_deck_02/dsa/tries/0211-design-add-and-search-words-data-structure.org

@@ -1,18 +1,97 @@
 #+PROPERTY: STUDY_DECK_02
 * TODO 0211. Design Add And Search Words Data Structure :medium:
 :PROPERTIES:
-:NEETCODE: [[file:../../roadmap.org::*0211. Design Add And Search Words Data Structure][Roadmap]]
+:NEETCODE: [[file:../../roadmap.org::*0211. Design Add And Search Words Data Structure][0211. Design Add And Search Words Data Structure]]
 :END:
 
+Design a data structure that supports adding new words and finding if a string matches any previously added string.
+
+Implement the ~WordDictionary~ class:
+
+ - ~WordDictionary()~ Initializes the object.
+
+ - ~void addWord(word)~ Adds ~word~ to the data structure, it can be matched later.
+
+ - ~bool search(word)~ Returns ~true~ if there is any string in the data structure that matches ~word~ or ~false~ otherwise. ~word~ may contain dots ~'.'~ where dots can be matched with any letter.
+
+*Example:*
+
+
+#+begin_src
+Input
+["WordDictionary","addWord","addWord","addWord","search","search","search","search"]
+[[],["bad"],["dad"],["mad"],["pad"],["bad"],[".ad"],["b.."]]
+Output
+[null,null,null,null,false,true,true,true]
+
+Explanation
+WordDictionary wordDictionary = new WordDictionary();
+wordDictionary.addWord("bad");
+wordDictionary.addWord("dad");
+wordDictionary.addWord("mad");
+wordDictionary.search("pad"); // return False
+wordDictionary.search("bad"); // return True
+wordDictionary.search(".ad"); // return True
+wordDictionary.search("b.."); // return True
+#+end_src
+
+
+*Constraints:*
+
+ - ~1 <= word.length <= 25~
+
+ - ~word~ in ~addWord~ consists of lowercase English letters.
+
+ - ~word~ in ~search~ consist of ~'.'~ or lowercase English letters.
+
+ - There will be at most ~2~ dots in ~word~ for ~search~ queries.
+
+ - At most ~10^{4}~ calls will be made to ~addWord~ and ~search~.
+
 ** TODO Approach
 Write your approach here.
 
 ** TODO Python
 #+begin_src python
+class WordDictionary:
 
+    def __init__(self):
+        
+
+    def addWord(self, word: str) -> None:
+        
+
+    def search(self, word: str) -> bool:
+        
+
+
+# Your WordDictionary object will be instantiated and called as such:
+# obj = WordDictionary()
+# obj.addWord(word)
+# param_2 = obj.search(word)
 #+end_src
 
 ** TODO C++
 #+begin_src cpp
+class WordDictionary {
+public:
+    WordDictionary() {
+        
+    }
+    
+    void addWord(string word) {
+        
+    }
+    
+    bool search(string word) {
+        
+    }
+};
 
+/**
+ * Your WordDictionary object will be instantiated and called as such:
+ * WordDictionary* obj = new WordDictionary();
+ * obj->addWord(word);
+ * bool param_2 = obj->search(word);
+ */
 #+end_src

org/study_deck_02/dsa/tries/0212-word-search-ii.org

@@ -1,18 +1,64 @@
 #+PROPERTY: STUDY_DECK_02
 * TODO 0212. Word Search II :hard:
 :PROPERTIES:
-:NEETCODE: [[file:../../roadmap.org::*0212. Word Search II][Roadmap]]
+:NEETCODE: [[file:../../roadmap.org::*0212. Word Search II][0212. Word Search II]]
 :END:
 
+Given an ~m x n~ ~board~ of characters and a list of strings ~words~, return /all words on the board/.
+
+Each word must be constructed from letters of sequentially adjacent cells, where *adjacent cells* are horizontally or vertically neighboring. The same letter cell may not be used more than once in a word.
+
+*Example 1:*
+
+
+#+begin_src
+Input: board = [["o","a","a","n"],["e","t","a","e"],["i","h","k","r"],["i","f","l","v"]], words = ["oath","pea","eat","rain"]
+Output: ["eat","oath"]
+#+end_src
+
+
+*Example 2:*
+
+
+#+begin_src
+Input: board = [["a","b"],["c","d"]], words = ["abcb"]
+Output: []
+#+end_src
+
+
+*Constraints:*
+
+ - ~m == board.length~
+
+ - ~n == board[i].length~
+
+ - ~1 <= m, n <= 12~
+
+ - ~board[i][j]~ is a lowercase English letter.
+
+ - ~1 <= words.length <= 3 * 10^{4}~
+
+ - ~1 <= words[i].length <= 10~
+
+ - ~words[i]~ consists of lowercase English letters.
+
+ - All the strings of ~words~ are unique.
+
 ** TODO Approach
 Write your approach here.
 
 ** TODO Python
 #+begin_src python
-
+class Solution:
+    def findWords(self, board: List[List[str]], words: List[str]) -> List[str]:
 #+end_src
 
 ** TODO C++
 #+begin_src cpp
-
+class Solution {
+public:
+    vector<string> findWords(vector<vector<char>>& board, vector<string>& words) {
+        
+    }
+};
 #+end_src

org/study_deck_02/dsa/tries/1166-design-file-system.org

@@ -1,7 +1,7 @@
 #+PROPERTY: STUDY_DECK_02
 * TODO 1166. Design File System :medium:
 :PROPERTIES:
-:NEETCODE: [[file:../../roadmap.org::*1166. Design File System][Roadmap]]
+:NEETCODE: [[file:../../roadmap.org::*1166. Design File System][1166. Design File System]]
 :END:
 
 ** TODO Approach