Create minimum-operations-to-make-a-special-number.py

Author: kamyu104

Python/minimum-operations-to-make-a-special-number.py

@@ -0,0 +1,17 @@
+# Time:  O(n)
+# Space; O(1)
+
+# math, greedy
+class Solution(object):
+    def minimumOperations(self, num):
+        """
+        :type num: str
+        :rtype: int
+        """
+        lookup = [0]*10
+        for i in reversed(xrange(len(num))):
+            if ((num[i] in "05" and lookup[0]) or
+                (num[i] in "27" and lookup[5])):
+                return (len(num)-i)-2
+            lookup[ord(num[i])-ord('0')] = 1
+        return len(num)-lookup[0]