Completed day 10

inputs/10.txt

@@ -0,0 +1,313 @@
+position=<-52775,  31912> velocity=< 5, -3>
+position=<-52816,  10731> velocity=< 5, -1>
+position=< 42573, -31652> velocity=<-4,  3>
+position=<-31611,  31918> velocity=< 3, -3>
+position=< 42585, -31656> velocity=<-4,  3>
+position=<-10428,  53102> velocity=< 1, -5>
+position=< 31958, -10460> velocity=<-3,  1>
+position=<-21020,  10723> velocity=< 2, -1>
+position=<-52770,  10731> velocity=< 5, -1>
+position=< 21400,  10728> velocity=<-2, -1>
+position=<-10427, -42253> velocity=< 1,  4>
+position=< 21343,  42515> velocity=<-2, -4>
+position=<-10417, -52846> velocity=< 1,  5>
+position=< 42558, -42251> velocity=<-4,  4>
+position=<-21008,  53106> velocity=< 2, -5>
+position=<-10443,  31912> velocity=< 1, -3>
+position=<-31584,  31919> velocity=< 3, -3>
+position=<-31604,  10726> velocity=< 3, -1>
+position=<-52786, -21055> velocity=< 5,  2>
+position=<-10394,  31918> velocity=< 1, -3>
+position=<-52786,  53109> velocity=< 5, -5>
+position=<-52770,  10722> velocity=< 5, -1>
+position=<-21007, -10464> velocity=< 2,  1>
+position=< 21392, -31657> velocity=<-2,  3>
+position=< 53180,  31913> velocity=<-5, -3>
+position=<-10393,  21319> velocity=< 1, -2>
+position=<-10430,  10724> velocity=< 1, -1>
+position=<-20985, -42245> velocity=< 2,  4>
+position=<-31610, -10468> velocity=< 3,  1>
+position=<-20989, -42247> velocity=< 2,  4>
+position=<-21006,  21317> velocity=< 2, -2>
+position=< 10752, -31651> velocity=<-1,  3>
+position=< 42577,  31912> velocity=<-4, -3>
+position=<-42196, -21059> velocity=< 4,  2>
+position=< 10744, -10460> velocity=<-1,  1>
+position=<-10443, -31658> velocity=< 1,  3>
+position=< 53185,  31912> velocity=<-5, -3>
+position=<-52790, -21063> velocity=< 5,  2>
+position=< 31990, -21060> velocity=<-3,  2>
+position=< 10776, -52845> velocity=<-1,  5>
+position=<-31636,  21324> velocity=< 3, -2>
+position=<-10395, -42249> velocity=< 1,  4>
+position=<-31591,  31912> velocity=< 3, -3>
+position=<-10430, -21063> velocity=< 1,  2>
+position=<-10422,  31912> velocity=< 1, -3>
+position=< 10800, -42250> velocity=<-1,  4>
+position=<-42199, -42248> velocity=< 4,  4>
+position=< 31950,  42515> velocity=<-3, -4>
+position=< 31982,  53104> velocity=<-3, -5>
+position=< 31982, -52845> velocity=<-3,  5>
+position=< 10752,  42510> velocity=<-1, -4>
+position=< 31958, -21054> velocity=<-3,  2>
+position=< 10752, -10467> velocity=<-1,  1>
+position=< 31977, -31649> velocity=<-3,  3>
+position=<-10438, -10460> velocity=< 1,  1>
+position=<-20983,  10726> velocity=< 2, -1>
+position=<-10385,  53109> velocity=< 1, -5>
+position=< 42590, -52839> velocity=<-4,  5>
+position=<-42180,  21317> velocity=< 4, -2>
+position=<-31592, -21063> velocity=< 3,  2>
+position=<-52782, -10466> velocity=< 5,  1>
+position=<-31604, -42251> velocity=< 3,  4>
+position=<-42198, -52848> velocity=< 4,  5>
+position=<-31632,  42513> velocity=< 3, -4>
+position=<-31601, -10468> velocity=< 3,  1>
+position=<-31632,  21320> velocity=< 3, -2>
+position=<-52773,  10725> velocity=< 5, -1>
+position=<-42205, -10459> velocity=< 4,  1>
+position=< 42533,  21322> velocity=<-4, -2>
+position=< 53181,  53106> velocity=<-5, -5>
+position=< 42533,  53102> velocity=<-4, -5>
+position=< 53185, -42248> velocity=<-5,  4>
+position=< 10797,  10730> velocity=<-1, -1>
+position=< 53137,  21326> velocity=<-5, -2>
+position=< 10776,  42508> velocity=<-1, -4>
+position=< 21387, -42249> velocity=<-2,  4>
+position=< 10805, -42250> velocity=<-1,  4>
+position=<-20990,  42512> velocity=< 2, -4>
+position=<-52801,  53102> velocity=< 5, -5>
+position=< 42554,  53111> velocity=<-4, -5>
+position=<-52809,  53106> velocity=< 5, -5>
+position=<-31588, -42249> velocity=< 3,  4>
+position=<-31595,  31921> velocity=< 3, -3>
+position=< 42553, -10468> velocity=<-4,  1>
+position=<-52818, -42249> velocity=< 5,  4>
+position=<-20999, -42244> velocity=< 2,  4>
+position=< 53127,  10731> velocity=<-5, -1>
+position=< 21347, -52842> velocity=<-2,  5>
+position=<-52794,  21323> velocity=< 5, -2>
+position=<-42214,  31912> velocity=< 4, -3>
+position=< 42558, -52847> velocity=<-4,  5>
+position=<-10414, -42244> velocity=< 1,  4>
+position=<-21025,  10728> velocity=< 2, -1>
+position=<-10398,  10727> velocity=< 1, -1>
+position=<-52794, -21056> velocity=< 5,  2>
+position=< 10800,  53103> velocity=<-1, -5>
+position=< 42556, -21059> velocity=<-4,  2>
+position=<-31610,  42516> velocity=< 3, -4>
+position=< 10780,  42507> velocity=<-1, -4>
+position=< 31987, -52840> velocity=<-3,  5>
+position=< 31952,  53102> velocity=<-3, -5>
+position=<-21033, -42250> velocity=< 2,  4>
+position=<-52773, -10466> velocity=< 5,  1>
+position=<-42199,  42511> velocity=< 4, -4>
+position=< 21355, -10467> velocity=<-2,  1>
+position=<-21029, -10459> velocity=< 2,  1>
+position=<-52775,  10727> velocity=< 5, -1>
+position=<-21009,  31915> velocity=< 2, -3>
+position=<-10389, -10464> velocity=< 1,  1>
+position=< 53156,  31921> velocity=<-5, -3>
+position=< 31995,  31920> velocity=<-3, -3>
+position=<-31620, -52839> velocity=< 3,  5>
+position=< 53158, -31654> velocity=<-5,  3>
+position=<-42205,  42512> velocity=< 4, -4>
+position=< 31950,  10725> velocity=<-3, -1>
+position=<-10430, -42250> velocity=< 1,  4>
+position=<-42206,  53102> velocity=< 4, -5>
+position=< 42573,  10730> velocity=<-4, -1>
+position=<-42178,  53111> velocity=< 4, -5>
+position=<-10385,  53106> velocity=< 1, -5>
+position=< 31955,  21320> velocity=<-3, -2>
+position=< 42558,  10731> velocity=<-4, -1>
+position=< 42585, -31656> velocity=<-4,  3>
+position=< 42558, -21063> velocity=<-4,  2>
+position=<-31612, -10461> velocity=< 3,  1>
+position=<-10398,  31921> velocity=< 1, -3>
+position=<-52765,  10724> velocity=< 5, -1>
+position=< 42553,  53109> velocity=<-4, -5>
+position=<-52810, -21061> velocity=< 5,  2>
+position=<-42181, -31654> velocity=< 4,  3>
+position=<-42175, -21058> velocity=< 4,  2>
+position=<-10427, -10468> velocity=< 1,  1>
+position=< 42529, -21055> velocity=<-4,  2>
+position=< 10752,  53109> velocity=<-1, -5>
+position=< 42561,  53107> velocity=<-4, -5>
+position=< 31958, -31649> velocity=<-3,  3>
+position=< 31968, -21063> velocity=<-3,  2>
+position=<-10402, -52840> velocity=< 1,  5>
+position=< 42565, -52848> velocity=<-4,  5>
+position=< 53184,  31916> velocity=<-5, -3>
+position=<-52797,  53111> velocity=< 5, -5>
+position=< 42558, -52847> velocity=<-4,  5>
+position=<-10394,  53106> velocity=< 1, -5>
+position=<-42199, -42252> velocity=< 4,  4>
+position=<-31592, -42250> velocity=< 3,  4>
+position=< 10765,  53104> velocity=<-1, -5>
+position=<-52794,  42509> velocity=< 5, -4>
+position=< 21371,  53107> velocity=<-2, -5>
+position=<-31616, -21063> velocity=< 3,  2>
+position=<-42170,  31913> velocity=< 4, -3>
+position=<-42199,  42513> velocity=< 4, -4>
+position=< 10797,  53104> velocity=<-1, -5>
+position=<-42175,  42511> velocity=< 4, -4>
+position=<-20993,  21326> velocity=< 2, -2>
+position=<-31588,  42513> velocity=< 3, -4>
+position=<-20989,  31919> velocity=< 2, -3>
+position=< 53140,  42509> velocity=<-5, -4>
+position=< 53172, -10464> velocity=<-5,  1>
+position=< 53128,  10724> velocity=<-5, -1>
+position=<-31592,  42512> velocity=< 3, -4>
+position=< 21347,  10724> velocity=<-2, -1>
+position=<-52818, -21058> velocity=< 5,  2>
+position=< 10794,  31912> velocity=<-1, -3>
+position=<-10414, -52845> velocity=< 1,  5>
+position=<-42219,  21326> velocity=< 4, -2>
+position=< 31952,  31912> velocity=<-3, -3>
+position=<-10413,  42507> velocity=< 1, -4>
+position=< 21387, -31657> velocity=<-2,  3>
+position=< 42557, -21054> velocity=<-4,  2>
+position=<-20997,  53104> velocity=< 2, -5>
+position=<-21014, -10468> velocity=< 2,  1>
+position=<-10442,  10723> velocity=< 1, -1>
+position=< 42572, -21054> velocity=<-4,  2>
+position=<-20991, -42249> velocity=< 2,  4>
+position=<-10435, -31649> velocity=< 1,  3>
+position=< 10770, -10463> velocity=<-1,  1>
+position=< 31958,  10730> velocity=<-3, -1>
+position=<-21015, -42244> velocity=< 2,  4>
+position=<-21039,  53111> velocity=< 2, -5>
+position=<-31592,  31919> velocity=< 3, -3>
+position=<-21022, -42249> velocity=< 2,  4>
+position=< 31966,  10729> velocity=<-3, -1>
+position=< 53167, -10468> velocity=<-5,  1>
+position=<-42183,  21324> velocity=< 4, -2>
+position=< 31955,  31915> velocity=<-3, -3>
+position=< 42572,  53111> velocity=<-4, -5>
+position=<-42170,  53102> velocity=< 4, -5>
+position=< 42590, -10466> velocity=<-4,  1>
+position=<-31609,  53106> velocity=< 3, -5>
+position=< 42533, -10467> velocity=<-4,  1>
+position=<-42215,  10731> velocity=< 4, -1>
+position=<-42170,  10722> velocity=< 4, -1>
+position=<-21004,  53102> velocity=< 2, -5>
+position=< 53167,  10722> velocity=<-5, -1>
+position=< 53132, -52844> velocity=<-5,  5>
+position=< 42529, -21055> velocity=<-4,  2>
+position=< 31960,  21322> velocity=<-3, -2>
+position=<-42175,  42507> velocity=< 4, -4>
+position=< 21342,  21326> velocity=<-2, -2>
+position=<-52774,  31916> velocity=< 5, -3>
+position=< 21355, -42248> velocity=<-2,  4>
+position=< 53140,  10727> velocity=<-5, -1>
+position=< 21368,  21317> velocity=<-2, -2>
+position=< 42585, -42246> velocity=<-4,  4>
+position=< 10805, -10459> velocity=<-1,  1>
+position=< 21383, -52845> velocity=<-2,  5>
+position=< 53133, -31649> velocity=<-5,  3>
+position=<-31580, -31658> velocity=< 3,  3>
+position=< 10792, -10463> velocity=<-1,  1>
+position=< 10768, -52840> velocity=<-1,  5>
+position=<-10420, -52848> velocity=< 1,  5>
+position=<-42203,  31912> velocity=< 4, -3>
+position=< 31974, -42245> velocity=<-3,  4>
+position=<-52778,  42515> velocity=< 5, -4>
+position=<-42170,  53106> velocity=< 4, -5>
+position=<-10398, -10462> velocity=< 1,  1>
+position=<-52799, -52848> velocity=< 5,  5>
+position=<-42175,  42515> velocity=< 4, -4>
+position=< 53142, -21059> velocity=<-5,  2>
+position=< 10772,  42510> velocity=<-1, -4>
+position=< 53137,  42516> velocity=<-5, -4>
+position=<-42187, -21062> velocity=< 4,  2>
+position=< 10805,  31914> velocity=<-1, -3>
+position=< 21348,  10731> velocity=<-2, -1>
+position=<-21023,  10726> velocity=< 2, -1>
+position=< 31950, -31655> velocity=<-3,  3>
+position=<-10386, -31654> velocity=< 1,  3>
+position=<-21025, -21062> velocity=< 2,  2>
+position=< 31966,  21318> velocity=<-3, -2>
+position=<-52776,  31912> velocity=< 5, -3>
+position=< 42569, -52841> velocity=<-4,  5>
+position=<-31592,  10724> velocity=< 3, -1>
+position=<-10429,  21317> velocity=< 1, -2>
+position=<-31584,  10729> velocity=< 3, -1>
+position=<-52818,  21320> velocity=< 5, -2>
+position=<-21016, -10468> velocity=< 2,  1>
+position=<-52791,  42507> velocity=< 5, -4>
+position=<-42199,  42515> velocity=< 4, -4>
+position=< 31982, -10467> velocity=<-3,  1>
+position=<-10442, -52848> velocity=< 1,  5>
+position=< 42565,  10726> velocity=<-4, -1>
+position=<-42187, -10468> velocity=< 4,  1>
+position=< 42561, -52841> velocity=<-4,  5>
+position=< 42549,  31916> velocity=<-4, -3>
+position=< 53180, -52842> velocity=<-5,  5>
+position=< 21347,  21326> velocity=<-2, -2>
+position=< 53151,  31921> velocity=<-5, -3>
+position=< 31938,  10726> velocity=<-3, -1>
+position=< 31942, -52848> velocity=<-3,  5>
+position=< 10788, -10464> velocity=<-1,  1>
+position=< 42590,  53103> velocity=<-4, -5>
+position=< 53180, -21055> velocity=<-5,  2>
+position=< 31935,  10731> velocity=<-3, -1>
+position=<-52802, -31651> velocity=< 5,  3>
+position=<-52776, -42249> velocity=< 5,  4>
+position=< 53185, -21062> velocity=<-5,  2>
+position=< 53159,  42511> velocity=<-5, -4>
+position=< 10772,  10722> velocity=<-1, -1>
+position=<-31593,  31912> velocity=< 3, -3>
+position=< 10795,  21322> velocity=<-1, -2>
+position=<-10436, -10459> velocity=< 1,  1>
+position=< 21388, -42249> velocity=<-2,  4>
+position=<-10405,  31921> velocity=< 1, -3>
+position=<-52801,  42513> velocity=< 5, -4>
+position=< 42573,  31915> velocity=<-4, -3>
+position=< 21355,  53109> velocity=<-2, -5>
+position=<-21025,  21323> velocity=< 2, -2>
+position=< 53140, -10467> velocity=<-5,  1>
+position=<-52767,  10726> velocity=< 5, -1>
+position=< 21347,  31912> velocity=<-2, -3>
+position=<-42183,  53107> velocity=< 4, -5>
+position=< 31942, -10460> velocity=<-3,  1>
+position=<-10401,  53102> velocity=< 1, -5>
+position=< 21400, -10459> velocity=<-2,  1>
+position=< 42579,  10722> velocity=<-4, -1>
+position=< 31936,  42516> velocity=<-3, -4>
+position=< 53128, -21056> velocity=<-5,  2>
+position=<-20997, -42253> velocity=< 2,  4>
+position=<-52777, -31658> velocity=< 5,  3>
+position=<-10430,  21325> velocity=< 1, -2>
+position=< 42545, -10464> velocity=<-4,  1>
+position=<-21017, -52839> velocity=< 2,  5>
+position=<-31584,  31912> velocity=< 3, -3>
+position=< 53168, -21056> velocity=<-5,  2>
+position=<-42199, -10459> velocity=< 4,  1>
+position=< 10803,  53106> velocity=<-1, -5>
+position=< 21371,  21317> velocity=<-2, -2>
+position=<-21040, -42244> velocity=< 2,  4>
+position=<-31577,  42511> velocity=< 3, -4>
+position=< 42573,  21322> velocity=<-4, -2>
+position=< 31990,  10728> velocity=<-3, -1>
+position=< 53175, -52844> velocity=<-5,  5>
+position=< 42561,  21323> velocity=<-4, -2>
+position=<-42223, -52840> velocity=< 4,  5>
+position=< 53152, -10468> velocity=<-5,  1>
+position=<-52785,  53111> velocity=< 5, -5>
+position=<-31632, -31656> velocity=< 3,  3>
+position=<-21009, -10466> velocity=< 2,  1>
+position=<-21025, -31651> velocity=< 2,  3>
+position=< 10795,  53106> velocity=<-1, -5>
+position=< 31978, -52844> velocity=<-3,  5>
+position=<-52774, -21059> velocity=< 5,  2>
+position=<-42211, -42253> velocity=< 4,  4>
+position=<-31580,  53107> velocity=< 3, -5>
+position=< 53172,  53102> velocity=<-5, -5>
+position=<-52773,  42508> velocity=< 5, -4>
+position=<-10398, -21054> velocity=< 1,  2>
+position=<-31607, -10466> velocity=< 3,  1>
+position=<-52801,  53108> velocity=< 5, -5>
+position=<-52813, -21054> velocity=< 5,  2>
+position=<-31600,  42511> velocity=< 3, -4>
+position=<-31631,  21317> velocity=< 3, -2>
+position=< 42532, -31649> velocity=<-4,  3>

inputs/10_test.txt

@@ -0,0 +1,31 @@
+position=< 9,  1> velocity=< 0,  2>
+position=< 7,  0> velocity=<-1,  0>
+position=< 3, -2> velocity=<-1,  1>
+position=< 6, 10> velocity=<-2, -1>
+position=< 2, -4> velocity=< 2,  2>
+position=<-6, 10> velocity=< 2, -2>
+position=< 1,  8> velocity=< 1, -1>
+position=< 1,  7> velocity=< 1,  0>
+position=<-3, 11> velocity=< 1, -2>
+position=< 7,  6> velocity=<-1, -1>
+position=<-2,  3> velocity=< 1,  0>
+position=<-4,  3> velocity=< 2,  0>
+position=<10, -3> velocity=<-1,  1>
+position=< 5, 11> velocity=< 1, -2>
+position=< 4,  7> velocity=< 0, -1>
+position=< 8, -2> velocity=< 0,  1>
+position=<15,  0> velocity=<-2,  0>
+position=< 1,  6> velocity=< 1,  0>
+position=< 8,  9> velocity=< 0, -1>
+position=< 3,  3> velocity=<-1,  1>
+position=< 0,  5> velocity=< 0, -1>
+position=<-2,  2> velocity=< 2,  0>
+position=< 5, -2> velocity=< 1,  2>
+position=< 1,  4> velocity=< 2,  1>
+position=<-2,  7> velocity=< 2, -2>
+position=< 3,  6> velocity=<-1, -1>
+position=< 5,  0> velocity=< 1,  0>
+position=<-6,  0> velocity=< 2,  0>
+position=< 5,  9> velocity=< 1, -2>
+position=<14,  7> velocity=<-2,  0>
+position=<-3,  6> velocity=< 2, -1>

inputs/10_test_one.txt

@@ -0,0 +1 @@
+position=< 0,  1> velocity=< 0,  0>

src/day10.rs

@@ -0,0 +1,247 @@
+extern crate regex;
+
+use std::collections::HashSet;
+use std::error::Error;
+use std::fmt;
+use std::fs;
+use std::result;
+use std::str::FromStr;
+
+use regex::Regex;
+
+type Result<T> = result::Result<T, Box<Error>>;
+
+const INPUT: &str = "inputs/10.txt";
+
+#[derive(Debug, PartialEq, Clone)]
+struct Vector {
+    x: i32,
+    y: i32,
+}
+
+#[derive(Debug, PartialEq)]
+struct Point {
+    position: Vector,
+    velocity: Vector,
+}
+
+impl FromStr for Point {
+    type Err = Box<Error>;
+
+    fn from_str(s: &str) -> Result<Point> {
+        lazy_static! {
+            static ref RE: Regex = Regex::new(concat!(
+                r"position=<(?P<position_x>(\s|-)?\d+), (?P<position_y>(\s|-)?\d+)> ",
+                r"velocity=<(?P<velocity_x>(\s|-)?\d+), (?P<velocity_y>(\s|-)?\d+)>"
+            ))
+            .unwrap();
+        }
+
+        let captures = match RE.captures(s) {
+            None => {
+                return Err(From::from("Malformed points, no fields could be found"));
+            }
+            Some(captures) => captures,
+        };
+
+        Ok(Point {
+            position: Vector {
+                x: captures["position_x"].trim_start().parse()?,
+                y: captures["position_y"].trim_start().parse()?,
+            },
+            velocity: Vector {
+                x: captures["velocity_x"].trim_start().parse()?,
+                y: captures["velocity_y"].trim_start().parse()?,
+            },
+        })
+    }
+}
+
+#[derive(Debug, PartialEq)]
+struct Sky {
+    points: Vec<Point>,
+}
+
+impl FromStr for Sky {
+    type Err = Box<Error>;
+
+    fn from_str(s: &str) -> Result<Sky> {
+        Ok(Sky {
+            points: s
+                .trim_end()
+                .split('\n')
+                .map(|line| line.parse().unwrap())
+                .collect(),
+        })
+    }
+}
+
+impl Sky {
+    fn point_spread(&self) -> (Vector, Vector) {
+        let mut min = self.points[0].position.clone();
+        let mut max = self.points[0].position.clone();
+
+        for point in self.points.iter() {
+            if point.position.x < min.x {
+                min.x = point.position.x;
+            }
+            if point.position.y < min.y {
+                min.y = point.position.y;
+            }
+            if point.position.x > max.x {
+                max.x = point.position.x;
+            }
+            if point.position.y > max.y {
+                max.y = point.position.y;
+            }
+        }
+
+        (min, max)
+    }
+
+    fn move_points(&mut self, seconds: i32) {
+        for point in self.points.iter_mut() {
+            point.position.x += point.velocity.x * seconds;
+            point.position.y += point.velocity.y * seconds;
+        }
+    }
+}
+
+impl fmt::Display for Sky {
+    #[allow(clippy::write_with_newline)]
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let (min, max) = self.point_spread();
+        let points_set: HashSet<(i32, i32)> = self
+            .points
+            .iter()
+            .map(|point| (point.position.x, point.position.y))
+            .collect();
+
+        for y in min.y..=max.y {
+            for x in min.x..=max.x {
+                if points_set.contains(&(x, y)) {
+                    write!(f, "#")?;
+                } else {
+                    write!(f, ".")?;
+                }
+            }
+            write!(f, "\n")?;
+        }
+        Ok(())
+    }
+}
+
+pub fn solve_parts() -> Result<(String, u32)> {
+    let mut sky = read_points_file(INPUT)?;
+    let (min, max) = sky.point_spread();
+    let mut min_spread = Vector {
+        x: (max.x - min.x).abs(),
+        y: (max.y - min.y).abs(),
+    };
+    let mut seconds = 0;
+
+    loop {
+        sky.move_points(1);
+        let (min, max) = sky.point_spread();
+        let spread_x = (max.x - min.x).abs();
+        let spread_y = (max.y - min.y).abs();
+
+        if spread_x > min_spread.x && spread_y > min_spread.y {
+            sky.move_points(-1);
+            return Ok((format!("{}", &sky), seconds));
+        }
+
+        if spread_x < min_spread.x {
+            min_spread.x = spread_x
+        }
+        if spread_y < min_spread.y {
+            min_spread.y = spread_y
+        }
+        seconds += 1;
+    }
+}
+
+fn read_points_file(filename: &str) -> Result<Sky> {
+    let points = fs::read_to_string(filename)?;
+    Ok(points.parse()?)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const TEST_INPUT_ONE: &str = "inputs/10_test_one.txt";
+    const TEST_INPUT: &str = "inputs/10_test.txt";
+    const TEST_POINT: Point = Point {
+        position: Vector { x: 0, y: 1 },
+        velocity: Vector { x: 0, y: 0 },
+    };
+    fn test_sky() -> Sky {
+        Sky {
+            points: vec![TEST_POINT],
+        }
+    }
+
+    #[test]
+    fn parses_string_to_point() {
+        let point = "position=< 0,  1> velocity=< 0,  0>";
+        assert_eq!(point.parse::<Point>().unwrap(), TEST_POINT);
+    }
+
+    #[test]
+    fn reads_points_file() {
+        assert_eq!(read_points_file(TEST_INPUT_ONE).unwrap(), test_sky());
+    }
+
+    #[test]
+    fn displays_sky_with_one_point() {
+        assert_eq!(format!("{}", test_sky()), ".\n#\n");
+    }
+
+    #[test]
+    fn displays_sky() {
+        let sky = read_points_file(TEST_INPUT).unwrap();
+        print!("{}", &sky);
+        assert_eq!(
+            format!("{}", sky),
+            concat!(
+                "........#.............\n",
+                "................#.....\n",
+                ".........#.#..#.......\n",
+                "......................\n",
+                "#..........#.#.......#\n",
+                "...............#......\n",
+                "....#.................\n",
+                "..#.#....#............\n",
+                ".......#..............\n",
+                "......#...............\n",
+                "...#...#.#...#........\n",
+                "....#..#..#.........#.\n",
+                ".......#..............\n",
+                "...........#..#.......\n",
+                "#...........#.........\n",
+                "...#.......#..........\n",
+            )
+        );
+    }
+
+    #[test]
+    fn displays_message_in_sky() {
+        let mut sky = read_points_file(TEST_INPUT).unwrap();
+        sky.move_points(3);
+        print!("{}", &sky);
+        assert_eq!(
+            format!("{}", sky),
+            concat!(
+                "#...#..###\n",
+                "#...#...#.\n",
+                "#...#...#.\n",
+                "#####...#.\n",
+                "#...#...#.\n",
+                "#...#...#.\n",
+                "#...#...#.\n",
+                "#...#..###\n",
+            )
+        );
+    }
+}

src/main.rs

@@ -12,6 +12,7 @@ mod day6;
 mod day7;
 mod day8;
 mod day9;
+mod day10;
 
 fn main() {
     // println!("Day 1:");
@@ -38,7 +39,11 @@ fn main() {
     // println!("Day 8:");
     // println!("{}", day8::solve_part1().unwrap());
     // println!("{}", day8::solve_part2().unwrap());
-    println!("Day 9:");
+    // println!("Day 9:");
     // println!("{}", day9::solve_part1().unwrap());
-    println!("{}", day9::solve_part2().unwrap());
+    // println!("{}", day9::solve_part2().unwrap());
+    println!("Day 10:");
+    let parts = day10::solve_parts().unwrap();
+    println!("{}", parts.0);
+    println!("{}", parts.1);
 }