Jun 07

Author: siddydutta

2025-06-June-LeetCoding-Challenge/Lexicographically Minimum String After Removing Stars.py

@@ -0,0 +1,31 @@
+class Solution:
+    def clearStars(self, s: str) -> str:
+        n = len(s)
+        indices = [[] for _ in range(26)]  # indices of each char
+        keep = [True] * n  # flag to keep index in result
+
+        for i in range(n):
+            if s[i] == '*':
+                keep[i] = False  # remove *
+                # find first (smallest) char's latest index
+                for j in range(26):
+                    if indices[j]:
+                        keep[indices[j].pop()] = False
+                        break
+            else:
+                # append index of current char
+                indices[ord(s[i]) - ord('a')].append(i)
+
+        return ''.join(s[i] for i in range(n) if keep[i])
+
+
+def main():
+    s = 'aaba*'
+    assert Solution().clearStars(s) == 'aab'
+
+    s = 'abc'
+    assert Solution().clearStars(s) == 'abc'
+
+
+if __name__ == '__main__':
+    main()

2025-06-June-LeetCoding-Challenge/README.md

@@ -10,7 +10,7 @@
 | June 04 | [3403. Find the Lexicographically Largest String From the Box I](https://leetcode.com/problems/find-the-lexicographically-largest-string-from-the-box-i/) | Medium | Solved |
 | June 05 | [1061. Lexicographically Smallest Equivalent String](https://leetcode.com/problems/lexicographically-smallest-equivalent-string) | Medium | Unsolved |
 | June 06 | [2434. Using a Robot to Print the Lexicographically Smallest String](https://leetcode.com/problems/using-a-robot-to-print-the-lexicographically-smallest-string/) | Medium | Unsolved |
-| June 07 | []() |  |  |
+| June 07 | [3170. Lexicographically Minimum String After Removing Stars](https://leetcode.com/problems/lexicographically-minimum-string-after-removing-stars/) | Medium | Solved |
 | June 08 | []() |  |  |
 | June 09 | []() |  |  |
 | June 10 | []() |  |  |
@@ -40,5 +40,5 @@
 | Level  | Problems | Solved | Unsolved |
 | ---    | --- | --- | --- |
 | Easy   | 0 | 0 | 0 |
-| Medium | 4 | 1 | 3 |
+| Medium | 5 | 2 | 3 |
 | Hard   | 2 | 2 | 0 |