Merge pull request vJechsmayr#190 from suparna13/master

0076_Minimum_Window_Substring

Author: vJechsmayr

LeetCode/0076_Minimum_Window_Substring.py

@@ -0,0 +1,31 @@
+from collections import defaultdict
+
+class Solution:
+ def minWindow(self, s: str, t: str) -> str:
+ char_frequency = defaultdict(lambda: 0)
+ for c in t:
+ char_frequency[c] += 1
+ chars_matched = 0
+
+ start = 0
+ res = ""
+
+ for end in range(len(s)):
+ right_char = s[end]
+ if right_char in t:
+ char_frequency[right_char] -= 1
+ if char_frequency[right_char] == 0:
+ chars_matched += 1
+
+ while start <= end and chars_matched == len(char_frequency):
+ if res == "" or end-start+1 < len(res):
+ res = s[start:end+1]
+
+ left_char = s[start]
+ if left_char in t:
+ if char_frequency[left_char] == 0:
+ chars_matched -= 1
+ char_frequency[left_char] += 1
+ start += 1
+
+ return res