Create words-within-two-edits-of-dictionary.py

Author: kamyu104

Python/words-within-two-edits-of-dictionary.py

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+# Time:  O(25 * l * (n + q))
+# Space: O(25 * l * n)
+
+import string
+
+
+# hash
+class Solution(object):
+    def twoEditWords(self, queries, dictionary):
+        """
+        :type queries: List[str]
+        :type dictionary: List[str]
+        :rtype: List[str]
+        """
+        MOD = (1<<64)-59  # largest 64-bit prime
+        BASE = 113
+        POW = [1]
+        def add(a, b):
+            return (a+b)%MOD
+
+        def mult(a, b):
+            return (a*b)%MOD
+
+        def pow(i):
+            while not (i < len(POW)):
+                POW.append(mult(POW[-1], BASE))
+            return POW[i]
+    
+        lookup = set()
+        for w in dictionary:
+            h = reduce(lambda h, i: add(h, mult(ord(w[i])-ord('a'), pow(i))), xrange(len(w)), 0)
+            for i, c in enumerate(w):
+                for x in string.ascii_lowercase:
+                    if x == c:
+                        continue
+                    lookup.add(add(h, mult(ord(x)-ord(c), pow(i))))
+        result = []
+        for w in queries:
+            h = reduce(lambda h, i: add(h, mult(ord(w[i])-ord('a'), pow(i))), xrange(len(w)), 0)
+            for i, c in enumerate(w):
+                for x in string.ascii_lowercase:
+                    if x == c:
+                        continue
+                    if add(h, mult(ord(x)-ord(c), pow(i))) in lookup:
+                        break
+                else:
+                    continue
+                result.append(w)
+                break
+        return result
+
+
+# Time:  O(q * n * l)
+# Space: O(1)
+import itertools
+
+
+# brute force
+class Solution2(object):
+    def twoEditWords(self, queries, dictionary):
+        """
+        :type queries: List[str]
+        :type dictionary: List[str]
+        :rtype: List[str]
+        """
+        return [q for q in queries if any(sum(c1 != c2 for c1, c2 in itertools.izip(q, d)) <= 2 for d in dictionary)]