Solve day6

4 files changed, 247 insertions, 0 deletions

diff --git a/day6/.vscode/launch.json b/day6/.vscode/launch.json
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+++ b/day6/.vscode/launch.json
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+{
+  // Use IntelliSense to learn about possible attributes.
+  // Hover to view descriptions of existing attributes.
+  // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "type": "lldb",
+      "request": "launch",
+      "name": "Debug executable 'day6'",
+      "cargo": {
+        "args": [
+          "build",
+          "--bin=day6",
+          "--package=day6"
+        ],
+        "filter": {
+          "kind": "bin"
+        }
+      },
+      "args": ["input.txt"],
+      "cwd": "${workspaceFolder}"
+    },
+    {
+      "type": "lldb",
+      "request": "launch",
+      "name": "Debug unit tests in executable 'day6'",
+      "cargo": {
+        "args": [
+          "test",
+          "--no-run",
+          "--bin=day6",
+          "--package=day6"
+        ],
+        "filter": {
+          "kind": "bin"
+        }
+      },
+      "args": [],
+      "cwd": "${workspaceFolder}"
+    }
+  ]
+}
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diff --git a/day6/Cargo.lock b/day6/Cargo.lock
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+++ b/day6/Cargo.lock
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+[[package]]
+name = "day6"
+version = "0.1.0"
+dependencies = [
+ "text_io 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "text_io"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[metadata]
+"checksum text_io 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "9658b61ebd1d2a40c276ba2335890b9eb6550b67458a6fbce2022e58c3350a50"
diff --git a/day6/Cargo.toml b/day6/Cargo.toml
new file mode 100644
index 0000000..0b3b5e0
--- /dev/null
+++ b/day6/Cargo.toml
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+[package]
+name = "day6"
+version = "0.1.0"
+authors = ["Jan Tuomi <jan.tuomi@eficode.com>"]
+
+[dependencies]
+text_io = "0.1.7"
diff --git a/day6/src/main.rs b/day6/src/main.rs
new file mode 100644
index 0000000..de2a2b5
--- /dev/null
+++ b/day6/src/main.rs
@@ -0,0 +1,183 @@
+use std::env;
+use std::io::BufReader;
+use std::io::BufRead;
+use std::fs::File;
+use std::process;
+
+#[macro_use] extern crate text_io;
+
+struct BoundingBox {
+  left: u32,
+  top: u32,
+  right: u32,
+  bottom: u32
+}
+
+struct Coordinate {
+  x: u32,
+  y: u32
+}
+
+struct Point {
+  coordinate: Coordinate,
+  id: u32
+}
+
+fn distance(a: &Coordinate, b: &Coordinate) -> u32 {
+  let dx = (a.x as i32 - b.x as i32).abs();
+  let dy = (a.y as i32 - b.y as i32).abs();
+  (dx + dy) as u32
+}
+
+fn find_closest(c: &Coordinate, points: &Vec<Point>) -> Option<(u32, u32)> {
+  let mut shortest = std::u32::MAX;
+  let mut point_id: Option<u32> = None;
+  for point in points {
+    let dist = distance(&point.coordinate, c);
+    if dist < shortest {
+      shortest = dist;
+      point_id = Some(point.id);
+    } else if dist == shortest {
+      point_id = None;
+    }
+  }
+
+  match point_id {
+    Some(id) => Some((id, shortest)),
+    None => None
+  }
+}
+
+fn find_total_distance_to_points(c: &Coordinate, points: &Vec<Point>) -> u32 {
+  let mut total: u32 = 0;
+  for point in points {
+    let dist = distance(c, &point.coordinate);
+    total += dist;
+  }
+  total
+}
+
+fn draw_grid(grid: &Vec<Vec<Option<u32>>>, bb: &BoundingBox) {
+  let w = (bb.right - bb.left + 1) as usize;
+  let h = (bb.bottom - bb.top + 1) as usize;
+  for j in 0..h {
+    for i in 0..w {
+      let x = (i as u32 + bb.left) as u32;
+      let y = (j as u32 + bb.top) as u32;
+      let id_opt = grid[j][i];
+      match id_opt {
+        Some(id) => { print!("{}", id); }
+        None => { print!("."); }
+      }
+    }
+    print!("\n");
+  }
+}
+
+fn find_largest_area(grid: &Vec<Vec<Option<u32>>>, points: &Vec<Point>, bb: &BoundingBox) -> u32 {
+  let w = (bb.right - bb.left + 1) as usize;
+  let h = (bb.bottom - bb.top + 1) as usize;
+  let mut largest_area = 0;
+  for point in points {
+    let mut area = 0;
+    for j in 0..h {
+      for i in 0..w {
+        let id_opt = grid[j][i];
+        match id_opt {
+          Some(id) => {
+            if id == point.id {
+              area += 1;
+            }
+          }
+          None => {}
+        }
+      }
+    }
+
+    if area > largest_area {
+      largest_area = area;
+    }
+  }
+
+  largest_area
+}
+
+fn main() {
+  let args: Vec<String> = env::args().collect();
+  if args.len() != 2 {
+    println!("Wrong number of arguments. Provide just a file name.");
+    process::exit(1);
+  }
+  let filename = &args[1];
+  println!("Using file {} as input.", filename);
+  let f = match File::open(filename) {
+    Ok(file) => file,
+    Err(e) => {
+      println!("Failed to open file {}. {:?}", filename, e);
+      process::exit(1);
+    }
+  };
+  let file = BufReader::new(&f);
+  let lines: Vec<String> = file.lines()
+    .map(|line| line.expect("Could not parse line."))
+    .collect();
+
+  let mut points: Vec<Point> = Vec::new();
+  let mut bb: BoundingBox = BoundingBox {
+    left: std::u32::MAX,
+    top: std::u32::MAX,
+    right: std::u32::MIN,
+    bottom: std::u32::MIN
+  };
+
+  for (i, line) in (&lines).iter().enumerate() {
+    let (x, y): (u32, u32);
+    scan!(line.bytes() => "{}, {}", x, y);
+    if x < bb.left { bb.left = x; }
+    if x > bb.right { bb.right = x; }
+    if y < bb.top { bb.top = y; }
+    if y > bb.bottom { bb.bottom = y; }
+
+    let coordinate = Coordinate { x, y };
+    points.push(Point { coordinate, id: i as u32 });
+    println!("Add point {}, {}", &x, &y);
+  }
+
+  println!("BB: l: {}, r: {}, top: {}, bot: {}", bb.left, bb.right, bb.top, bb.bottom);
+
+  let w = (bb.right - bb.left + 1) as usize;
+  let h = (bb.bottom - bb.top + 1) as usize;
+  let mut grid: Vec<Vec<Option<u32>>> = vec![vec![None; w]; h];
+  for j in 0..h {
+    for i in 0..w {
+      let x = (i as u32 + bb.left) as u32;
+      let y = (j as u32 + bb.top) as u32;
+      let coord = Coordinate { x, y };
+      let opt: Option<(u32, u32)> = find_closest(&coord, &points);
+      match opt {
+        Some((id, shortest)) => { grid[j][i] = Some(id); }
+        None => { grid[j][i] = None }
+      }
+    }
+  }
+
+  //draw_grid(&grid, &bb);
+  let largest_area_1 = find_largest_area(&grid, &points, &bb);
+  println!("1. Largest area: {}", largest_area_1);
+
+  let threshold = 10000;
+  let mut largest_area_2 = 0;
+  for j in 0..h {
+    for i in 0..w {
+      let x = (i as u32 + bb.left) as u32;
+      let y = (j as u32 + bb.top) as u32;
+      let coord = Coordinate { x, y };
+      let total_dist = find_total_distance_to_points(&coord, &points);
+      if total_dist < threshold {
+        largest_area_2 += 1;
+      }
+    }
+  }
+
+  println!("2. Largest area: {}", largest_area_2);
+}
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