Adding solution of 1008 and 1007

Author: Garvit244

1000-1100q/1007.py

@@ -0,0 +1,38 @@
+'''
+In a row of dominoes, A[i] and B[i] represent the top and bottom halves of the i-th domino.  (A domino is a tile with two numbers from 1 to 6 - one on each half of the tile.)
+
+We may rotate the i-th domino, so that A[i] and B[i] swap values.
+
+Return the minimum number of rotations so that all the values in A are the same, or all the values in B are the same.
+
+If it cannot be done, return -1.
+Input: A = [2,1,2,4,2,2], B = [5,2,6,2,3,2]
+Output: 2
+Explanation: 
+The first figure represents the dominoes as given by A and B: before we do any rotations.
+If we rotate the second and fourth dominoes, we can make every value in the top row equal to 2, as indicated by the second figure.
+'''
+
+class Solution(object):
+    def minDominoRotations(self, A, B):
+        """
+        :type A: List[int]
+        :type B: List[int]
+        :rtype: int
+        """
+        if len(A) != len(B):
+            return -1
+        if len(A) == 0:
+            return 0
+        
+        for possibility in set([A[0], B[0]]):
+            top_rotation, bottom_rotation =0, 0
+            for a_num, b_num in zip(A, B):
+                if possibility not in [a_num, b_num]:
+                    break
+                top_rotation += int(b_num != possibility)
+                bottom_rotation += int(a_num != possibility)
+            else:
+                return min(top_rotation, bottom_rotation)
+        return -1
+ 

1000-1100q/1008.py

@@ -0,0 +1,33 @@
+'''
+Return the root node of a binary search tree that matches the given preorder traversal.
+
+(Recall that a binary search tree is a binary tree where for every node, any descendant of node.left has a value < node.val, and any descendant of node.right has a value > node.val.  Also recall that a preorder traversal displays the value of the node first, then traverses node.left, then traverses node.right.)
+'''
+
+# Definition for a binary tree node.
+# class TreeNode(object):
+#     def __init__(self, x):
+#         self.val = x
+#         self.left = None
+#         self.right = None
+
+class Solution(object):
+    def bstFromPreorder(self, preorder):
+        """
+        :type preorder: List[int]
+        :rtype: TreeNode
+        """
+        root = TreeNode(preorder[0])
+        stack = [root]
+        for index in range(1, len(preorder)):
+            new_node = TreeNode(preorder[index])
+            if new_node.val < stack[-1].val:
+                stack[-1].left = new_node
+            else:
+                parent = None
+                while stack and new_node.val > stack[-1].val:
+                    parent = stack.pop()
+                parent.right = new_node
+            stack.append(new_node)
+        return root
+        

README.md

@@ -14,6 +14,8 @@ Python solution of problems from [LeetCode](https://leetcode.com/).
 |1014|[Capacity To Ship Packages Within D Days](https://leetcode.com/problems/capacity-to-ship-packages-within-d-days/) | [Python](./1000-1100q/1014.py) | Medium|
 |1013|[Pairs of Songs With Total Durations Divisible by 60](https://leetcode.com/problems/pairs-of-songs-with-total-durations-divisible-by-60/)|[Python](./1000-1100q/1013.py)|Easy|
 |1012|[Complement of Base 10 Integer](https://leetcode.com/problems/complement-of-base-10-integer/) | [Python](./1000-1100q/1012.py)|Easy|
+|1008|[Construct Binary Search Tree from Preorder Traversal](https://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversal)|[Python](./1000-1100q/1008.py)|Medium|
+|1007|[Minimum Domino Rotations For Equal Row](https://leetcode.com/problems/minimum-domino-rotations-for-equal-row)|[Python](./1000-1100q/1007.py)|Medium|
 |1004|[Max Consecutive Ones III](https://leetcode.com/problems/max-consecutive-ones-iii)|[Python](./1000-1100q/1004.py)|Medium|
 |1003|[Check If Word Is Valid After Substitutions](https://leetcode.com/problems/check-if-word-is-valid-after-substitutions)|[Python](./1000-1100q/1003.py)|Medium|
 |1002|[Find Common Characters](https://leetcode.com/problems/find-common-characters)|[Python](./1000-1100q/1002.py)|Easy|