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| author | kaiwu <kaiwu2004@gmail.com> | 2023-01-20 21:48:43 +0800 |
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| committer | kaiwu <kaiwu2004@gmail.com> | 2023-01-20 21:48:43 +0800 |
| commit | 546b50d29ea292f330061e7ac007535d5e949798 (patch) | |
| tree | a868ba9c00dc55b31f451654c9bba63ea5825e21 /src/2016 | |
| parent | 7f9d12aec6e9bb37ad8f02550f24406827c4c691 (diff) | |
| download | advent-of-code-546b50d29ea292f330061e7ac007535d5e949798.tar.gz advent-of-code-546b50d29ea292f330061e7ac007535d5e949798.zip | |
2016 day13 part1
Diffstat (limited to 'src/2016')
| -rw-r--r-- | src/2016/day13/README.md | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/src/2016/day13/README.md b/src/2016/day13/README.md index e69de29..577401b 100644 --- a/src/2016/day13/README.md +++ b/src/2016/day13/README.md @@ -0,0 +1,41 @@ +--- Day 13: A Maze of Twisty Little Cubicles --- + +You arrive at the first floor of this new building to discover a much less welcoming environment than the shiny atrium of the last one. Instead, you are in a maze of twisty little cubicles, all alike. + +Every location in this area is addressed by a pair of non-negative integers (x,y). Each such coordinate is either a wall or an open space. You can't move diagonally. The cube maze starts at 0,0 and seems to extend infinitely toward positive x and y; negative values are invalid, as they represent a location outside the building. You are in a small waiting area at 1,1. + +While it seems chaotic, a nearby morale-boosting poster explains, the layout is actually quite logical. You can determine whether a given x,y coordinate will be a wall or an open space using a simple system: + + Find x*x + 3*x + 2*x*y + y + y*y. + Add the office designer's favorite number (your puzzle input). + Find the binary representation of that sum; count the number of bits that are 1. + If the number of bits that are 1 is even, it's an open space. + If the number of bits that are 1 is odd, it's a wall. + +For example, if the office designer's favorite number were 10, drawing walls as # and open spaces as ., the corner of the building containing 0,0 would look like this: + + 0123456789 +0 .#.####.## +1 ..#..#...# +2 #....##... +3 ###.#.###. +4 .##..#..#. +5 ..##....#. +6 #...##.### + +Now, suppose you wanted to reach 7,4. The shortest route you could take is marked as O: + + 0123456789 +0 .#.####.## +1 .O#..#...# +2 #OOO.##... +3 ###O#.###. +4 .##OO#OO#. +5 ..##OOO.#. +6 #...##.### + +Thus, reaching 7,4 would take a minimum of 11 steps (starting from your current location, 1,1). + +What is the fewest number of steps required for you to reach 31,39? + +Your puzzle input is 1352. |