solution: 0076. Minimum Window Substring

Author: flynnpark

Diff for: solutions/solution_0076/__init__.py

@@ -1,2 +1,40 @@
+from collections import defaultdict
+
+
 class Solution:
-    def minWindow(self, s: str, t: str) -> str: ...
+    def minWindow(self, s: str, t: str) -> str:
+        if len(s) < len(t):
+            return ''
+
+        t_map: defaultdict[str, int] = defaultdict(int)
+        t_length = len(t)
+
+        for char in t:
+            t_map[char] += 1
+
+        left = 0
+        result = (0, len(s) + 1)
+
+        for right, char in enumerate(s):
+            if t_map[char] > 0:
+                t_length -= 1
+
+            t_map[char] -= 1
+
+            if t_length == 0:
+                while True:
+                    current_left = s[left]
+                    if t_map[current_left] == 0:
+                        break
+
+                    t_map[current_left] += 1
+                    left += 1
+
+                if right - left < result[1] - result[0]:
+                    result = (left, right)
+
+                t_map[s[left]] += 1
+                t_length += 1
+                left += 1
+
+        return s[result[0] : result[1] + 1] if result[1] != float('inf') else ''