11

8 files changed, 452 insertions, 0 deletions

diff --git a/11/Cargo.toml b/11/Cargo.toml
new file mode 100644
index 0000000..c35a8db
--- /dev/null
+++ b/11/Cargo.toml
@@ -0,0 +1,11 @@
+[package]
+name = "advent_11"
+version = "0.1.0"
+authors = ["Irene Knapp <ireneista@gmail.com>"]
+edition = "2018"
+
+[dependencies]
+advent_lib = { path = "../lib" }
+
+[dev-dependencies]
+assert_cmd = "0.10"
diff --git a/11/input b/11/input
new file mode 100644
index 0000000..6a466bd
--- /dev/null
+++ b/11/input
@@ -0,0 +1,98 @@
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diff --git a/11/input.small b/11/input.small
new file mode 100644
index 0000000..1beaede
--- /dev/null
+++ b/11/input.small
@@ -0,0 +1,10 @@
+L.LL.LL.LL
+LLLLLLL.LL
+L.L.L..L..
+LLLL.LL.LL
+L.LL.LL.LL
+L.LLLLL.LL
+..L.L.....
+LLLLLLLLLL
+L.LLLLLL.L
+L.LLLLL.LL
diff --git a/11/src/main.rs b/11/src/main.rs
new file mode 100644
index 0000000..1ea6365
--- /dev/null
+++ b/11/src/main.rs
@@ -0,0 +1,275 @@
+use advent_lib::prelude::*;
+
+use std::convert::TryFrom;
+
+
+#[derive(Clone,Debug,PartialEq)]
+pub enum CellState {
+  Floor,
+  EmptySeat,
+  FullSeat,
+}
+
+
+pub fn debug_grid(grid: &Vec<Vec<CellState>>) {
+  let mut output = String::new();
+
+  for row in grid {
+    for cell in row {
+      match cell {
+        CellState::Floor => {
+          output.push_str(".");
+        }
+        CellState::EmptySeat => {
+          output.push_str("L");
+        }
+        CellState::FullSeat => {
+          output.push_str("#");
+        }
+      }
+    }
+    output.push_str("\n");
+  }
+  output.push_str("\n");
+  println!("{}", output);
+}
+
+
+fn main() -> Result<()> {
+  let mut args = std::env::args();
+  if args.len() != 2 {
+    eprintln!("Usage: advent input");
+  }
+  let _ = args.next();
+  let filename = args.next().unwrap();
+
+  let input = advent_lib::read_lines_file(&filename)?;
+
+  let mut original_grid: Vec<Vec<CellState>> = Vec::new();
+
+  for line in &input {
+    let mut row: Vec<CellState> = Vec::new();
+
+    for c in line.chars() {
+      if c == 'L' {
+        row.push(CellState::EmptySeat);
+      } else {
+        row.push(CellState::Floor);
+      }
+    }
+
+    original_grid.push(row);
+  }
+
+  let mut grid = original_grid.clone();
+  let nearby_seats = compute_nearby_seats(&original_grid);
+
+  loop {
+    let (any_changed, new_grid) = simulate_one(&grid);
+    if !any_changed {
+      break;
+    }
+    grid = new_grid;
+  }
+
+  println!("{}", count_full_seats(&grid));
+
+  let mut grid = original_grid.clone();
+
+  let mut n_iterations = 0;
+
+  loop {
+    let (any_changed, new_grid) = simulate_distancey_one(&grid, &nearby_seats);
+    if !any_changed {
+      break;
+    }
+    grid = new_grid;
+    n_iterations += 1;
+    if n_iterations % 1000 == 0 {
+      println!("iteration {}", n_iterations);
+      debug_grid(&grid);
+    }
+  }
+
+  println!("{}", count_full_seats(&grid));
+
+  Ok(())
+}
+
+
+fn simulate_one(input_grid: &Vec<Vec<CellState>>) -> (bool, Vec<Vec<CellState>>) {
+  let mut output_grid: Vec<Vec<CellState>> = Vec::new();
+  let mut any_changed = false;
+
+  for y in 0 .. input_grid.len() {
+    let mut output_row: Vec<CellState> = Vec::new();
+
+    for x in 0 .. input_grid[y].len() {
+      let mut adjacent_count = 0;
+
+      let mut nearby_x_min = x;
+      if nearby_x_min > 0 {
+        nearby_x_min -= 1;
+      }
+
+      let mut nearby_x_max = x;
+      if nearby_x_max + 1 < input_grid[y].len() {
+        nearby_x_max += 1;
+      }
+
+      let mut nearby_y_min = y;
+      if nearby_y_min > 0 {
+        nearby_y_min -= 1;
+      }
+
+      let mut nearby_y_max = y;
+      if nearby_y_max + 1 < input_grid.len() {
+        nearby_y_max += 1;
+      }
+
+      for nearby_x in nearby_x_min .. nearby_x_max + 1 {
+        for nearby_y in nearby_y_min .. nearby_y_max + 1 {
+          if nearby_x == x && nearby_y == y {
+            continue;
+          }
+
+          let nearby_cell = &input_grid[nearby_y][nearby_x];
+
+          if *nearby_cell == CellState::FullSeat {
+            adjacent_count += 1;
+          }
+        }
+      }
+
+      let input_cell = &input_grid[y][x];
+      if *input_cell == CellState::Floor {
+        output_row.push(CellState::Floor);
+      } else if *input_cell == CellState::EmptySeat && adjacent_count == 0 {
+        output_row.push(CellState::FullSeat);
+        any_changed = true;
+      } else if *input_cell == CellState::FullSeat && adjacent_count >= 4 {
+        output_row.push(CellState::EmptySeat);
+        any_changed = true;
+      } else {
+        output_row.push(input_cell.clone());
+      }
+    }
+
+    output_grid.push(output_row);
+  }
+
+  (any_changed, output_grid)
+}
+
+
+fn simulate_distancey_one(
+    input_grid: &Vec<Vec<CellState>>,
+    nearby_seats: &Vec<Vec<Vec<(usize, usize)>>>)
+  -> (bool, Vec<Vec<CellState>>)
+{
+  let mut output_grid: Vec<Vec<CellState>> = Vec::new();
+  let mut any_changed = false;
+
+  for y in 0 .. input_grid.len() {
+    let mut output_row: Vec<CellState> = Vec::new();
+
+    for x in 0 .. input_grid[y].len() {
+      let mut adjacent_count = 0;
+
+      for (nearby_x, nearby_y) in &nearby_seats[y][x] {
+        let nearby_cell = &input_grid[*nearby_y][*nearby_x];
+
+        if *nearby_cell == CellState::FullSeat {
+          adjacent_count += 1;
+        }
+      }
+
+      let input_cell = &input_grid[y][x];
+      if *input_cell == CellState::Floor {
+        output_row.push(CellState::Floor);
+      } else if *input_cell == CellState::EmptySeat && adjacent_count == 0 {
+        output_row.push(CellState::FullSeat);
+        any_changed = true;
+      } else if *input_cell == CellState::FullSeat && adjacent_count >= 5 {
+        output_row.push(CellState::EmptySeat);
+        any_changed = true;
+      } else {
+        output_row.push(input_cell.clone());
+      }
+    }
+
+    output_grid.push(output_row);
+  }
+
+  (any_changed, output_grid)
+}
+
+
+fn compute_nearby_seats(input_grid: &Vec<Vec<CellState>>)
+  -> Vec<Vec<Vec<(usize, usize)>>>
+{
+  let mut nearby_seats: Vec<Vec<Vec<(usize, usize)>>> = Vec::new();
+
+  let mut max_dimension: isize = isize::try_from(input_grid.len()).unwrap();
+  if isize::try_from(input_grid[0].len()).unwrap() > max_dimension {
+    max_dimension = isize::try_from(input_grid[0].len()).unwrap();
+  }
+
+  for y in 0 .. input_grid.len() {
+    let mut nearby_seats_row: Vec<Vec<(usize, usize)>> = Vec::new();
+
+    for x in 0 .. input_grid[y].len() {
+      let mut nearby_seats_one: Vec<(usize, usize)> = Vec::new();
+
+      for (dx, dy) in [
+        (-1, -1), (0, -1), (1, -1), (-1, 0), (1, 0), (-1, 1), (0, 1), (1, 1) ].iter()
+      {
+        for distance in 1 .. max_dimension {
+          let nearby_y = isize::try_from(y).unwrap() + dy * distance;
+          let nearby_x = isize::try_from(x).unwrap() + dx * distance;
+
+          if nearby_y < 0 || usize::try_from(nearby_y).unwrap() >= input_grid.len() {
+            break;
+          }
+
+          if nearby_x < 0 || usize::try_from(nearby_x).unwrap()
+              >= input_grid[usize::try_from(nearby_y).unwrap()].len()
+          {
+            break;
+          }
+
+          let nearby_cell = &input_grid[usize::try_from(nearby_y).unwrap()]
+            [usize::try_from(nearby_x).unwrap()];
+
+          if *nearby_cell == CellState::FullSeat || *nearby_cell == CellState::EmptySeat {
+            nearby_seats_one.push((usize::try_from(nearby_x).unwrap(),
+                usize::try_from(nearby_y).unwrap()));
+            break;
+          }
+        }
+      }
+
+      nearby_seats_row.push(nearby_seats_one);
+    }
+
+    nearby_seats.push(nearby_seats_row);
+  }
+
+  nearby_seats
+}
+
+
+fn count_full_seats(grid: &Vec<Vec<CellState>>) -> i64 {
+  let mut count = 0;
+
+  for row in grid {
+    for cell in row {
+      if *cell == CellState::FullSeat {
+        count += 1;
+      }
+    }
+  }
+
+  count
+}
+
diff --git a/11/tests/main.rs b/11/tests/main.rs
new file mode 100644
index 0000000..c09af93
--- /dev/null
+++ b/11/tests/main.rs
@@ -0,0 +1,14 @@
+use assert_cmd::prelude::*;
+use std::process::Command;
+
+
+#[test]
+fn personal_input() -> Result<(), Box<dyn std::error::Error>> {
+  let mut command = Command::cargo_bin("advent_11")?;
+
+  command.arg("input");
+  command.assert().success().stdout("2406\n2149\n");
+
+  Ok(())
+}
+
diff --git a/Cargo.lock b/Cargo.lock
index 272770c..1c31fa8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -83,6 +83,14 @@ dependencies = [
 ]
 
 [[package]]
+name = "advent_11"
+version = "0.1.0"
+dependencies = [
+ "advent_lib",
+ "assert_cmd",
+]
+
+[[package]]
 name = "advent_lib"
 version = "0.1.0"
 
diff --git a/Cargo.nix b/Cargo.nix
index f5b6f81..785f38c 100644
--- a/Cargo.nix
+++ b/Cargo.nix
@@ -128,6 +128,16 @@ rec {
       # File a bug if you depend on any for non-debug work!
       debug = internal.debugCrate { inherit packageId; };
     };
+    "advent_11" = rec {
+      packageId = "advent_11";
+      build = internal.buildRustCrateWithFeatures {
+        packageId = "advent_11";
+      };
+
+      # Debug support which might change between releases.
+      # File a bug if you depend on any for non-debug work!
+      debug = internal.debugCrate { inherit packageId; };
+    };
     "advent_lib" = rec {
       packageId = "advent_lib";
       build = internal.buildRustCrateWithFeatures {
@@ -418,6 +428,31 @@ rec {
         ];
         
       };
+      "advent_11" = rec {
+        crateName = "advent_11";
+        version = "0.1.0";
+        edition = "2018";
+        crateBin = [
+          { name = "advent_11"; path = "src/main.rs"; }
+        ];
+        src = (builtins.filterSource sourceFilter ./11);
+        authors = [
+          "Irene Knapp <ireneista@gmail.com>"
+        ];
+        dependencies = [
+          {
+            name = "advent_lib";
+            packageId = "advent_lib";
+          }
+        ];
+        devDependencies = [
+          {
+            name = "assert_cmd";
+            packageId = "assert_cmd";
+          }
+        ];
+        
+      };
       "advent_lib" = rec {
         crateName = "advent_lib";
         version = "0.1.0";
diff --git a/Cargo.toml b/Cargo.toml
index 35009be..abc26f4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,4 +11,5 @@ members = [
   "08",
   "09",
   "10",
+  "11",
 ]