Create longest-well-performing-interval.py

Author: kamyu104

Python/longest-well-performing-interval.py

@@ -0,0 +1,22 @@
+# Time:  O(n)
+# Space: O(n)
+
+class Solution(object):
+    def longestWPI(self, hours):
+        """
+        :type hours: List[int]
+        :rtype: int
+        """
+        result, accu = 0, 0
+        lookup = {}
+        for i, h in enumerate(hours):
+            accu = accu+1 if h > 8 else accu-1
+            if accu > 0:
+                result = i+1
+            elif accu-1 in lookup:
+                # lookup[accu-1] is the leftmost idx with smaller accu,
+                # because from 1 to some positive k,
+                # lookup[accu-i] is a strickly increasing sequence
+                result = max(result, i-lookup[accu-1])
+            lookup.setdefault(accu, i)
+        return result