upd

org/study_deck_02/dsa/arrays-hashing/0001-two-sum.org

@@ -57,6 +57,12 @@ Write your approach here.
 #+begin_src python
 class Solution:
     def twoSum(self, nums: List[int], target: int) -> List[int]:
+        sb = {}
+        for xi, x in enumerate(nums):
+            want = target - x;
+            if want in sb:
+                return sb[want], xi
+            sb[x] = xi
 #+end_src
 
 ** TODO C++

org/study_deck_02/dsa/arrays-hashing/0347-top-k-frequent-elements.org

@@ -40,9 +40,11 @@ Given an integer array ~nums~ and an integer ~k~, return /the/ ~k~ /most frequen
 Write your approach here.
 
 ** TODO Python
-#+begin_src python
+#+begin_src python :lc-problem 347 :lc-lang python3
 class Solution:
     def topKFrequent(self, nums: List[int], k: int) -> List[int]:
+        from collections import Counter
+        return [n for n, _ in Counter(nums).most_common(k)]
 #+end_src
 
 ** TODO C++

org/study_deck_02/dsa/arrays-hashing/1408-string-matching-in-an-array.org

@@ -52,10 +52,40 @@ Write your approach here.
 
 ** TODO Python
 #+begin_src python
+from collections import defaultdict as dd
 class Solution:
     def stringMatching(self, words: List[str]) -> List[str]:
+        words = reversed(sorted(words))
+        def squash(word, trie):
+            lst = []
+            for c in word:
+                lst.append([trie, ''])
+                for i in range(len(lst)):
+                    lst[i][0] = lst[i][0][c]
+                    lst[i][1] += c
+                    if not lst[i][0]['ads']:
+                        lst[i][0]['ads'] = {lst[i][1]: [word]}
+                    else:
+                        lst[i][0]['ads'][lst[i][1]].append(word)
+        def in_trie(word, trie):
+            for c in word:
+                if c not in trie:
+                    return []
+                trie = trie[c]
+            return [(word, bw) for bw in trie['ads'][word]]
+        trie_maker = lambda: dd(trie_maker)
+        trie = trie_maker()
+        ans = []
+        for s in words:
+            ans += in_trie(s, trie)
+            squash(s, trie)
+        return ans
+
+
 #+end_src
 
+**
+
 ** TODO C++
 #+begin_src cpp
 class Solution {