daily

Author: Zanger67

my-submissions/m1415.py

@@ -0,0 +1,28 @@
+class Solution:
+    # _pm_dfs stands for premature dfs
+    def _pm_dfs(self, rem: int, n: int, output: List[str]) -> str :
+        if not n :
+            return ''.join(output)
+
+        pot_per_path = 2 ** (n - 1)
+        (options := ['a', 'b', 'c']).remove(output[-1])
+
+        if rem <= pot_per_path :
+            output.append(options[0])
+            return self._pm_dfs(rem, n - 1, output)
+        output.append(options[1])
+        return self._pm_dfs(rem - pot_per_path, n - 1, output)
+
+    def getHappyString(self, n: int, k: int) -> str:
+        n -= 1
+        pot_n_min_1 = 2 ** n
+
+        match (k - 1) // pot_n_min_1 :
+            case 0 :
+                return self._pm_dfs(k, n, ['a'])
+            case 1 :
+                return self._pm_dfs(k - pot_n_min_1, n, ['b'])
+            case 2 :
+                return self._pm_dfs(k - 2 * pot_n_min_1, n, ['c'])
+            case _ :
+                return ''