Added rotated mirror number

Author: Yan Cao

Interviews/Rotated_Mirror_Number.py

@@ -0,0 +1,40 @@
+"""
+####From Alec's email, someone's onsite interview with Facebook for finding rotated mirrow number like 808 which is less than N
+
+"""
+
+def rotated_mirror_number(n):
+    length = 0
+    while n - 10**length > 0:
+        length += 1
+    ret = []
+    rotated_helper(n, length, [], ret)
+    return ret
+
+def rotated_helper(n, length, res, ret):
+    num = convert_to_num(res)
+    if num > n or len(res) > length:
+        return
+    if len(res) > 0 and res[0] != 0:
+        ret.append(num)
+    if len(res) == 0:
+        for i in range(10):
+            res.append(i)
+            rotated_helper(n, length, res, ret)
+            res.pop()
+
+    for i in range(10):
+        res.append(i)
+        res.insert(0,i)
+        rotated_helper(n, length, res, ret)
+        res.pop()
+        res.pop(0)
+
+def convert_to_num(int_list):
+    res = 0
+    for digit in int_list:
+        res = res*10 + digit
+    return res
+
+
+print rotated_mirror_number(10000)