Create count-pairs-of-equal-substrings-with-minimum-difference.py

Author: kamyu104

Python/count-pairs-of-equal-substrings-with-minimum-difference.py

@@ -0,0 +1,25 @@
+# Time:  O(n)
+# Space: O(1)
+
+class Solution(object):
+    def countQuadruples(self, firstString, secondString):
+        """
+        :type firstString: str
+        :type secondString: str
+        :rtype: int
+        """
+        lookup1 = [-1]*26
+        for i in reversed(xrange(len(firstString))):
+            lookup1[ord(firstString[i])-ord('a')] = i
+        lookup2 = [-1]*26
+        for i in xrange(len(secondString)):
+            lookup2[ord(secondString[i])-ord('a')] = i
+        result, diff = 0, float("inf")
+        for i in xrange(26):
+            if lookup1[i] == -1 or lookup2[i] == -1:
+                continue
+            if lookup1[i]-lookup2[i] < diff:
+                diff = lookup1[i]-lookup2[i]
+                result = 0
+            result += int(lookup1[i]-lookup2[i] == diff)
+        return result