666. Path Sum IV

If the depth of a tree is smaller than 5 , then this tree can be represented by a list of three-digits integers.

For each integer in this list:

  1. The hundreds digit represents the depth D of this node, 1 <= D <= 4.
  2. The tens digit represents the position P of this node in the level it belongs to, 1 <= P <= 8 . The position is the same as that in a full binary tree.
  3. The units digit represents the value V of this node, 0 <= V <= 9.

 

Given a list of ascending three-digits integers representing a binary tree with the depth smaller than 5, you need to return the sum of all paths from the root towards the leaves.

Example 1:

Input:

 [113, 215, 221]
Output:

 12
Explanation:

 
The tree that the list represents is:
    3
   / \
  5   1
The path sum is (3 + 5) + (3 + 1) = 12.

 

Example 2:

Input:

 [113, 221]
Output:

 4
Explanation:

 
The tree that the list represents is: 
    3
     \
      1
The path sum is (3 + 1) = 4.

 

Difficulty:

Medium

Lock:

Prime

Company:

Alibaba