Create valid-anagram.py

Python/valid-anagram.py

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+# Time:  O(n)
+# Space: O(1)
+#
+# Given two strings s and t, write a function to
+# determine if t is an anagram of s.
+#
+# For example,
+# s = "anagram", t = "nagaram", return true.
+# s = "rat", t = "car", return false.
+#
+# Note:
+# You may assume the string contains only lowercase alphabets.
+#
+
+class Solution:
+    # @param {string} s
+    # @param {string} t
+    # @return {boolean}
+    def isAnagram(self, s, t):
+        if len(s) != len(t):
+            return False
+
+        count = {}
+
+        for c in s:
+            if c.lower() in count:
+                count[c.lower()] += 1
+            else:
+                count[c.lower()] = 1
+
+        for c in t:
+            if c.lower() in count:
+                count[c.lower()] -= 1
+            else:
+                count[c.lower()] = -1
+            if count[c.lower()] < 0:
+                return False
+
+        return True
+
+# Time:  O(nlogn)
+# Space: O(n)
+class Solution2:
+    # @param {string} s
+    # @param {string} t
+    # @return {boolean}
+    def isAnagram(self, s, t):
+        return sorted(s) == sorted(t)