Create contiguous-array.py

Author: kamyu104

Python/contiguous-array.py

@@ -0,0 +1,32 @@
+# Time:  O(n)
+# Space: O(n)
+
+# Given a binary array, find the maximum length of a contiguous subarray with equal number of 0 and 1.
+#
+# Example 1:
+# Input: [0,1]
+# Output: 2
+# Explanation: [0, 1] is the longest contiguous subarray with equal number of 0 and 1.
+# Example 2:
+# Input: [0,1,0]
+# Output: 2
+# Explanation: [0, 1] (or [1, 0]) is a longest contiguous subarray with equal number of 0 and 1.
+# Note: The length of the given binary array will not exceed 50,000.
+
+class Solution(object):
+    def findMaxLength(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: int
+        """
+        result, count = 0, 0
+        lookup = {0: 0}
+
+        for i, num in enumerate(nums):
+            count += 1 if num == 1 else -1
+            if count in lookup:
+                result = max(result, i+1 - lookup[count])
+            else:
+                lookup[count] = i+1
+        
+        return result