Update maximum-product-of-the-length-of-two-palindromic-substrings.py

Author: kamyu104

Python/maximum-product-of-the-length-of-two-palindromic-substrings.py

@@ -1,7 +1,51 @@
 # Time:  O(n)
 # Space: O(n)
 
+import collections
+
+
 class Solution(object):
+    def maxProduct(self, s):
+        """
+        :type s: str
+        :rtype: int
+        """
+        def manacher(s):
+            s = '^#' + '#'.join(s) + '#$'
+            P = [0]*len(s)
+            C, R = 0, 0
+            for i in xrange(1, len(s)-1):
+                i_mirror = 2*C-i
+                if R > i:
+                    P[i] = min(R-i, P[i_mirror])
+                while s[i+1+P[i]] == s[i-1-P[i]]:
+                    P[i] += 1
+                if i+P[i] > R:
+                    C, R = i, i+P[i]
+            return P
+
+        P = manacher(s)
+        q = collections.deque()
+        left = [0]
+        for i in xrange(len(s)):
+            while q and q[0][1] < i:
+                q.popleft()
+            left.append(max(left[-1], 1+2*(i-q[0][0]) if q else 1))
+            q.append((i, i+P[2*i+2]//2))
+        q = collections.deque()
+        result = right = 0
+        for i in reversed(xrange(len(s))):
+            while q and q[0][1] > i:
+                q.popleft()
+            right = max(right, 1+2*(q[0][0]-i) if q else 1)
+            q.append((i, i-P[2*i+2]//2))
+            result = max(result, left[i]*right)
+        return result
+
+
+# Time:  O(n)
+# Space: O(n)
+class Solution2(object):
     def maxProduct(self, s):
         """
         :type s: str