Create reconstruct-original-digits-from-english.py

Author: kamyu104

Python/reconstruct-original-digits-from-english.py

@@ -0,0 +1,49 @@
+# Time:  O(n)
+# Space: O(1)
+
+# Given a non-empty string containing an out-of-order English representation
+# of digits 0-9, output the digits in ascending order.
+#
+# Note:
+# Input contains only lowercase English letters.
+# Input is guaranteed to be valid and can be transformed to its original digits.
+# That means invalid inputs such as "abc" or "zerone" are not permitted.
+# Input length is less than 50,000.
+# Example 1:
+# Input: "owoztneoer"
+#
+# Output: "012"
+# Example 2:
+# Input: "fviefuro"
+#
+# Output: "45"
+
+from collections import Counter
+
+class Solution(object):
+    def originalDigits(self, s):
+        """
+        :type s: str
+        :rtype: str
+        """
+        # The count of each char in each number string.
+        cnts = [Counter(_) for _ in ["zero", "one", "two", "three", \
+                                     "four", "five", "six", "seven", \
+                                     "eight", "nine"]]
+        
+        # The order for greedy method.
+        order = [0, 2, 4, 6, 8, 1, 3, 5, 7, 9]
+        
+        # The unique char in the order.
+        unique_chars = ['z', 'o', 'w', 't', 'u', \
+                        'f', 'x', 's', 'g', 'n']
+
+        cnt = Counter(list(s))
+        res = []
+        for i in order:
+            while cnt[unique_chars[i]] > 0:
+                cnt -= cnts[i]
+                res.append(i)
+        res.sort()
+
+        return "".join(map(str, res))