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--- Day 8: Memory Maneuver ---
The sleigh is much easier to pull than you'd expect for something its weight. Unfortunately, neither
you nor the Elves know which way the North Pole is from here.
You check your wrist device for anything that might help. It seems to have some kind of navigation
system! Activating the navigation system produces more bad news: "Failed to start navigation
system. Could not read software license file."
The navigation system's license file consists of a list of numbers (your puzzle input). The numbers
define a data structure which, when processed, produces some kind of tree that can be used to
calculate the license number.
The [1m[97mtree[0m is made up of [1m[97mnodes[0m; a single, outermost node forms the tree's [1m[97mroot[0m, and it contains all
other nodes in the tree (or contains nodes that contain nodes, and so on).
Specifically, a node consists of:
- A [1m[97mheader[0m, which is always exactly two numbers:
- The quantity of child nodes.
- The quantity of metadata entries.
- Zero or more [1m[97mchild nodes[0m (as specified in the header).
- One or more [1m[97mmetadata entries[0m (as specified in the header).
Each child node is itself a node that has its own header, child nodes, and metadata. For example:
2 3 0 3 10 11 12 1 1 0 1 99 2 1 1 2
A----------------------------------
B----------- C-----------
D-----
In this example, each node of the tree is also marked with an underline starting with a letter for
easier identification. In it, there are four nodes:
- A, which has 2 child nodes (B, C) and 3 metadata entries (1, 1, 2).
- B, which has 0 child nodes and 3 metadata entries (10, 11, 12).
- C, which has 1 child node (D) and 1 metadata entry (2).
- D, which has 0 child nodes and 1 metadata entry (99).
The first check done on the license file is to simply add up all of the metadata entries. In this
example, that sum is 1+1+2+10+11+12+2+99=[1m[97m138[0m.
[1m[97mWhat is the sum of all metadata entries?[0m
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