Day 12: Rain Risk

After the keynote in the amphitheater, you need to head over to the Bocal to collect some hardware. But with corridors under construction, skybridges, and convoluted detours between 42's buildings, navigation is quite a puzzle.

The Bocal's campus navigation app transmits a sequence of instructions (your puzzle input). Each line consists of an action letter and an integer value:

• N means to move North by the given value.
• S means to move South by the given value.
• E means to move East by the given value.
• W means to move West by the given value.
• L means to turn left the given number of degrees.
• R means to turn right the given number of degrees.
• F means to move forward in the direction you are currently facing.

Part 1

You start at coordinates (0, 0) facing East.

Actions N, S, E, and W move you without changing the direction you are facing. Only actions L and R rotate your heading.

Example

Consider this sequence of navigation instructions:

F10
N3
F7
R90
F11

Here is how they execute step by step:

• F10 : moves 10 units East -> position (10, 0), still facing East.
• N3 : moves 3 units North -> position (10, 3), still facing East.
• F7 : moves 7 units East -> position (17, 3), still facing East.
• R90 : turns 90° right -> now facing South (position unchanged).
• F11 : moves 11 units South -> final position (17, -8).

The Manhattan distance (|x| + |y|) from the starting location is: |17| + |-8| = 25.

Execute the instructions from your own input. What is the Manhattan distance between that location and your starting position?