diff 2017/day03/problem @ 34:049fb8e56025

Add problem statements and inputs
author Jordi Gutiérrez Hermoso <jordigh@octave.org>
date Tue, 09 Jan 2018 21:51:44 -0500
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+--- Day 3: Spiral Memory ---
+
+You come across an experimental new kind of memory stored on an
+infinite two-dimensional grid.
+
+Each square on the grid is allocated in a spiral pattern starting at a
+location marked 1 and then counting up while spiraling outward. For
+example, the first few squares are allocated like this:
+
+17  16  15  14  13
+18   5   4   3  12
+19   6   1   2  11
+20   7   8   9  10
+21  22  23---> ...
+
+While this is very space-efficient (no squares are skipped), requested
+data must be carried back to square 1 (the location of the only access
+port for this memory system) by programs that can only move up, down,
+left, or right. They always take the shortest path: the Manhattan
+Distance between the location of the data and square 1.
+
+For example:
+
+    Data from square 1 is carried 0 steps, since it's at the access port.
+
+    Data from square 12 is carried 3 steps, such as: down, left, left.
+
+    Data from square 23 is carried only 2 steps: up twice.
+
+    Data from square 1024 must be carried 31 steps.
+
+How many steps are required to carry the data from the square
+identified in your puzzle input all the way to the access port?
+
+Your puzzle answer was 371.
+
+--- Part Two ---
+
+As a stress test on the system, the programs here clear the grid and
+then store the value 1 in square 1. Then, in the same allocation order
+as shown above, they store the sum of the values in all adjacent
+squares, including diagonals.
+
+So, the first few squares' values are chosen as follows:
+
+    Square 1 starts with the value 1.
+
+    Square 2 has only one adjacent filled square (with value 1), so it
+    also stores 1.
+
+    Square 3 has both of the above squares as neighbors and stores the
+    sum of their values, 2.
+
+    Square 4 has all three of the aforementioned squares as neighbors
+    and stores the sum of their values, 4.
+
+    Square 5 only has the first and fourth squares as neighbors, so it
+    gets the value 5.
+
+
+Once a square is written, its value does not change. Therefore, the
+first few squares would receive the following values:
+
+147  142  133  122   59
+304    5    4    2   57
+330   10    1    1   54
+351   11   23   25   26
+362  747  806--->   ...
+
+What is the first value written that is larger than your puzzle input?
+
+Your puzzle answer was 369601.
+
+Both parts of this puzzle are complete! They provide two gold stars: **