Add Py solution to LC1302

Author: kate-melnykova

LC1302-Deepest-Leaves-Sum.py

@@ -0,0 +1,53 @@
+"""
+Given the root of a binary tree, return the sum of values
+of its deepest leaves.
+
+Example 1:
+Input: root = [1,2,3,4,5,null,6,7,null,null,null,null,8]
+Output: 15
+
+Example 2:
+Input: root = [6,7,8,2,7,1,3,9,null,1,4,null,null,null,5]
+Output: 19
+
+
+Constraints:
+(*) The number of nodes in the tree is in the range [1, 10^4].
+(*) 1 <= Node.val <= 100
+"""
+from TreeNode import TreeNode
+
+# Definition for a binary tree node.
+# class TreeNode:
+#     def __init__(self, val=0, left=None, right=None):
+#         self.val = val
+#         self.left = left
+#         self.right = right
+class Solution:
+    def deepestLeavesSum(self, root: TreeNode) -> int:
+        if root is None:
+            return 0
+
+        level_new = [root, ]
+        while level_new:
+            level = list(level_new)
+            level_new = list()
+            for node in level:
+                if node.left is not None:
+                    level_new.append(node.left)
+                if node.right is not None:
+                    level_new.append(node.right)
+        return sum(node.val for node in level)
+
+
+if __name__ == "__main__":
+    import run_tests
+
+    correct_answers = [
+        [[1,2,3,4,5,None,6,7,None,None,None,None,8], 15],
+        [[6,7,8,2,7,1,3,9,None,1,4,None,None,None,5], 19]
+    ]
+    for i in range(len(correct_answers)):
+        correct_answers[i][0] = TreeNode.to_treenode(correct_answers[i][0])
+    print(f"Running tests for deepestLeavesSum")
+    run_tests.run_tests(Solution().deepestLeavesSum, correct_answers)