Create build-array-from-permutation.py

Author: kamyu104

Python/build-array-from-permutation.py

@@ -0,0 +1,30 @@
+# Time:  O(n)
+# Space: O(1)
+
+# inplace solution
+class Solution(object):
+    def buildArray(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: List[int]
+        """
+        for i in xrange(len(nums)):
+            prev, curr = i, nums[i]
+            while curr >= 0 and curr != i:
+                nums[prev], nums[curr] = ~nums[curr], ~nums[prev] if prev == i else nums[prev]
+                prev, curr = curr, ~nums[prev]
+        for i in xrange(len(nums)):
+            if nums[i] < 0:
+                nums[i] = ~nums[i]
+        return nums
+
+
+# Time:  O(n)
+# Space: O(1)
+class Solution2(object):
+    def buildArray(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: List[int]
+        """
+        return [nums[x] for x in nums]