2019: Day 3

2019/input_03.txt

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+R1003,D430,L108,D570,R459,U7,L68,D232,L130,U93,R238,U951,L821,U723,L370,U873,L680,U749,R110,U17,R185,U484,R550,U356,L212,U350,L239,D208,R666,U70,L369,U448,R54,D402,R165,D375,L468,U886,L303,U779,L752,U664,L120,U643,R405,D288,L220,U727,L764,D615,R630,U688,R961,U499,L782,D852,L743,U443,R355,U856,L795,U235,L876,D511,L108,U637,R427,D338,L699,D911,L506,D607,L539,U977,R654,D634,L196,U944,R922,D774,R358,U828,L970,D386,R795,U602,R249,U793,L171,D217,L476,D123,L179,U820,R895,D239,R363,D629,L226,D811,R962,D848,R218,D581,R369,D872,L653,D281,R304,D302,R780,U636,L413,D712,L642,D886,R613,U736,L968,D82,R953,U408,L130,U654,R312,U74,L610,D798,R242,D586,L808,D664,L764,U455,R264,U384,L154,D484,R883,D276,L423,U11,L145,U156,L268,U46,R202,U641,R920,D483,R859,U94,L173,D796,R11,D328,R48,D161,L615,D396,R350,D48,R946,D233,R385,D294,R640,D301,R810,D824,L969,D469,R34,U995,R750,D827,R52,U606,R143,U868,L973,U863,L17,U995,L236,U994,R403,D312,R49,U143,L399,U821,R974,U119,R410,D233,R228,D326,R112,D512,L950,D103,L590,U80,R7,U441,L744,U643,L80,D631,L576,U680,R369,U741,L87,D748,R773,U145,R464,U546,R80,D251,L972,U414,L390,U148,L84,D481,L425,U293,L564,U880,R535,U703,R981,U944,R224,D366,R29,U517,R342,U686,L384,D650,R983,D287,L108,U713,L523,U695,R881,D126,R151,U153,R161,D791,L599,D936,L816,U387,R411,U637,L434,D22,L720,U579,L661,D644,L220,U325,R753,D392,L503,U617,R1,D956,L607,U602,L800,D749,L193,U215,L91,U733,L606,U510,L124,D550,R303,D835,R19,D326,R577,U265,L156,D924,L122,D186,R803,U3,R879
+L1003,U603,L675,U828,R671,U925,R466,D707,L39,U1,R686,U946,L438,U626,R714,D365,L336,D624,R673,U672,L729,D965,R824,D533,R513,D914,R829,U275,L424,U10,L244,U158,R779,D590,R116,U714,R662,D989,R869,D547,R817,U315,R439,D29,L599,D870,L645,U656,R845,U19,R960,U669,L632,D567,L340,U856,R955,D314,R452,D896,R574,D162,R240,U302,R668,U706,R394,D24,L422,U884,R804,U576,L802,U400,R405,U676,L344,D628,R672,U580,R710,U536,L712,U738,L266,D212,R552,D229,R265,U835,R152,U784,L478,D87,L783,D327,R728,U590,R408,D397,R363,D654,R501,D583,R445,U897,R888,D480,R455,U593,R906,D506,R985,D361,R361,D619,L462,D873,L248,D348,R540,D578,L274,D472,R254,U647,R54,U681,L33,U343,R913,U120,L64,D849,L953,U407,L64,U744,L482,U240,L82,U69,R480,D796,L137,U527,R428,U67,R123,U688,L985,D944,R583,D804,R331,U328,R906,U376,L966,U433,R863,D931,L315,D9,L77,D141,L738,D661,R742,D44,R383,U78,R106,D301,L186,U907,L304,U786,L256,U718,R861,D145,R694,D721,R607,D418,R358,U600,R228,D139,R476,D451,L49,U616,L491,U8,R371,D735,R669,U388,L905,D282,L430,U491,L775,U891,L831,U350,L247,D609,R489,U266,R468,D748,R134,U187,R882,D315,R344,D363,R349,U525,R831,U644,R207,D563,L1,D946,L559,U789,L187,U370,L284,D910,L394,D560,L705,U661,R272,U109,L12,D554,L670,D169,L375,D100,R382,D491,L53,D916,R152,U82,L236,U845,L860,U732,R327,D190,R888,U722,R770,U993,R509,D970,L225,D756,R444,D992,L746,D35,R329,D452,R728,U575,L325,U414,L709,D844,R692,D575,R132,D520,L506,D384,L581,U36,L336,U849,L944,U450,R138,D186,L613,U805,R32,U763,R210,U556,R125,D499,R729

2019/src/bin/puzzle_03.rs

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+use std::collections::HashMap;
+use std::collections::HashSet;
+use std::convert::From;
+use std::io;
+use std::ops::Add;
+
+#[derive(Copy, Clone)]
+enum Direction {
+    Up,
+    Down,
+    Left,
+    Right,
+}
+
+impl From<char> for Direction {
+    fn from(v: char) -> Self {
+        match v {
+            'U' => Direction::Up,
+            'D' => Direction::Down,
+            'L' => Direction::Left,
+            'R' => Direction::Right,
+            _ => unreachable!(),
+        }
+    }
+}
+
+struct Vector {
+    direction: Direction,
+    magnitude: u32,
+}
+
+#[derive(Copy, Clone, Hash, Eq, PartialEq)]
+struct Coordinate(i32, i32);
+
+impl Coordinate {
+    fn manhattan_distance(&self, Coordinate(x, y): Coordinate) -> u32 {
+        x.abs_diff(self.0) + y.abs_diff(self.1)
+    }
+}
+
+impl Add for Coordinate {
+    type Output = Self;
+
+    fn add(self, other: Self) -> Self {
+        Self(self.0 + other.0, self.1 + other.1)
+    }
+}
+
+fn trace_path(path: &Vec<Vector>) -> HashMap<Coordinate, u32> {
+    let mut trace = HashMap::new();
+
+    let mut c = Coordinate(0, 0);
+    let mut len = 0;
+
+    for &Vector {
+        direction,
+        magnitude,
+    } in path
+    {
+        let step = match direction {
+            Direction::Up => Coordinate(0, 1),
+            Direction::Down => Coordinate(0, -1),
+            Direction::Left => Coordinate(-1, 0),
+            Direction::Right => Coordinate(1, 0),
+        };
+
+        for _ in 0..magnitude {
+            c = c + step;
+            len += 1;
+            trace.entry(c).or_insert(len);
+        }
+    }
+
+    trace
+}
+
+fn main() {
+    let wire_paths: Vec<Vec<Vector>> = io::stdin()
+        .lines()
+        .map(|line| line.unwrap())
+        .map(|path| {
+            path.split(',')
+                .map(|s| Vector {
+                    direction: Direction::from(s.as_bytes()[0] as char),
+                    magnitude: s[1..].parse().unwrap(),
+                })
+                .collect()
+        })
+        .collect();
+
+    assert!(wire_paths.len() == 2, "Only two wire paths expected!");
+
+    let trace1 = trace_path(&wire_paths[0]);
+    let trace2 = trace_path(&wire_paths[1]);
+
+    let keys1: HashSet<_> = HashSet::from_iter(trace1.keys().copied());
+    let keys2: HashSet<_> = HashSet::from_iter(trace2.keys().copied());
+
+    let intersections = keys1.intersection(&keys2);
+
+    println!(
+        "Part 1: {}",
+        intersections
+            .clone()
+            .map(|c| c.manhattan_distance(Coordinate(0, 0)))
+            .min()
+            .unwrap()
+    );
+
+    println!(
+        "Part 2: {}",
+        intersections
+            .map(|c| trace1.get(c).unwrap() + trace2.get(c).unwrap())
+            .min()
+            .unwrap()
+    );
+}