6 files changed, 106 insertions, 0 deletions
diff --git a/06/Cargo.toml b/06/Cargo.toml
new file mode 100644
index 0000000..e5303bd
--- /dev/null
+++ b/06/Cargo.toml
@@ -0,0 +1,11 @@
+[package]
+name = "advent_06"
+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/06/input b/06/input
new file mode 100644
index 0000000..e9ab820
--- /dev/null
+++ b/06/input
@@ -0,0 +1 @@
+1,1,1,1,2,1,1,4,1,4,3,1,1,1,1,1,1,1,1,4,1,3,1,1,1,5,1,3,1,4,1,2,1,1,5,1,1,1,1,1,1,1,1,1,1,3,4,1,5,1,1,1,1,1,1,1,1,1,3,1,4,1,1,1,1,3,5,1,1,2,1,1,1,1,4,4,1,1,1,4,1,1,4,2,4,4,5,1,1,1,1,2,3,1,1,4,1,5,1,1,1,3,1,1,1,1,5,5,1,2,2,2,2,1,1,2,1,1,1,1,1,3,1,1,1,2,3,1,5,1,1,1,2,2,1,1,1,1,1,3,2,1,1,1,4,3,1,1,4,1,5,4,1,4,1,1,1,1,1,1,1,1,1,1,2,2,4,5,1,1,1,1,5,4,1,3,1,1,1,1,4,3,3,3,1,2,3,1,1,1,1,1,1,1,1,2,1,1,1,5,1,3,1,4,3,1,3,1,5,1,1,1,1,3,1,5,1,2,4,1,1,4,1,4,4,2,1,2,1,3,3,1,4,4,1,1,3,4,1,1,1,2,5,2,5,1,1,1,4,1,1,1,1,1,1,3,1,5,1,2,1,1,1,1,1,4,4,1,1,1,5,1,1,5,1,2,1,5,1,1,1,1,1,1,1,1,1,1,1,1,3,2,4,1,1,2,1,1,3,2
diff --git a/06/src/main.rs b/06/src/main.rs
new file mode 100644
index 0000000..fa48fb0
--- /dev/null
+++ b/06/src/main.rs
@@ -0,0 +1,68 @@
+use advent_lib::prelude::*;
+
+
+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 time_buckets = Vec::new();
+  for word in input[0].split(',') {
+    let time = word.parse::<i64>()?;
+    while time_buckets.len() <= time as usize {
+      time_buckets.push(0);
+    }
+    time_buckets[time as usize] += 1;
+  }
+
+  for _ in 0 .. 80 {
+    time_buckets = iterate(&time_buckets);
+  }
+
+  println!("{}", population_size(&time_buckets));
+
+  for _ in 80 .. 256 {
+    time_buckets = iterate(&time_buckets);
+  }
+
+  println!("{}", population_size(&time_buckets));
+
+  Ok(())
+}
+
+
+fn iterate(old_time_buckets: &Vec<i64>) -> Vec<i64> {
+  let mut new_time_buckets = Vec::new();
+
+  while new_time_buckets.len() <= 8 {
+    new_time_buckets.push(0);
+  }
+
+  for (i, n) in old_time_buckets.iter().enumerate() {
+    if i == 0 {
+      new_time_buckets[6] += n;
+      new_time_buckets[8] += n;
+    } else {
+      new_time_buckets[i - 1] += n;
+    }
+  }
+
+  new_time_buckets
+}
+
+
+fn population_size(time_buckets: &Vec<i64>) -> i64 {
+  let mut result = 0;
+
+  for n in time_buckets {
+    result += n;
+  }
+
+  result
+}
+
diff --git a/06/tests/main.rs b/06/tests/main.rs
new file mode 100644
index 0000000..ad291d8
--- /dev/null
+++ b/06/tests/main.rs
@@ -0,0 +1,17 @@
+use assert_cmd::prelude::*;
+//use predicates::prelude::*;
+use std::process::Command;
+
+
+#[test]
+fn personal_input() -> Result<(), Box<dyn std::error::Error>> {
+  let mut command = Command::cargo_bin("advent_05")?;
+
+  command.arg("input");
+  command.assert().success().stdout(
+      "4655\n\
+      20500\n");
+
+  Ok(())
+}
+
diff --git a/Cargo.lock b/Cargo.lock
index 288f919..8f6d6d1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -41,6 +41,14 @@ dependencies = [
 ]
 
 [[package]]
+name = "advent_06"
+version = "0.1.0"
+dependencies = [
+ "advent_lib",
+ "assert_cmd",
+]
+
+[[package]]
 name = "advent_lib"
 version = "0.1.0"
 dependencies = [
diff --git a/Cargo.toml b/Cargo.toml
index 682e0be..6a830cc 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,4 +6,5 @@ members = [
   "03",
   "04",
   "05",
+  "06",
 ]