Days 4, 5 and 6

17 files changed, 2009 insertions, 0 deletions

diff --git a/04/Cargo.toml b/04/Cargo.toml
new file mode 100644
index 0000000..b98bd9d
--- /dev/null
+++ b/04/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+name = "day-04"
+version = "0.1.0"
+authors = ["Gard Spreemann <gspr@nonempty.org>"]
+edition = "2021"
+
+[[bin]]
+name = "part-1"
+path = "src/part-1.rs"
+
+[[bin]]
+name = "part-2"
+path = "src/part-2.rs"
+
+[dependencies]
diff --git a/04/input.txt b/04/input.txt
new file mode 100644
index 0000000..bcf9e87
--- /dev/null
+++ b/04/input.txt
@@ -0,0 +1,1000 @@
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diff --git a/04/src/part-1.rs b/04/src/part-1.rs
new file mode 100644
index 0000000..ee1d428
--- /dev/null
+++ b/04/src/part-1.rs
@@ -0,0 +1,62 @@
+use std::cmp::{Ordering, PartialOrd};
+use std::fmt::{Debug};
+use std::io::{BufRead};
+use std::str::FromStr;
+
+#[derive(Debug, Eq, PartialEq)]
+struct Interval<T: Eq + Ord + PartialOrd> {
+    a: T,
+    b: T
+}
+
+impl<T: Eq + Ord + PartialOrd> PartialOrd for Interval<T> {
+    fn partial_cmp(self: & Self, other: & Self) -> Option<Ordering> {
+        if self == other {
+            Some(Ordering::Equal)
+        }
+        else if self.a >= other.a && self.b <= other.b {
+            Some(Ordering::Less)
+        }
+        else if self.a <= other.a && self.b >= other.b {
+            Some(Ordering::Greater)
+        }
+        else {
+            None
+        }
+    }
+}
+
+
+impl<T: Debug + Eq + FromStr + Ord + PartialOrd> FromStr for Interval<T> {
+    type Err = <T as FromStr>::Err;
+
+    fn from_str(s: & str) -> Result<Self, Self::Err> {
+        let mut split = s.split('-');
+        let a: T = split.next().expect("FIXME: Turn into actual error.").parse().expect("FIXME");
+        let b: T = split.next().expect("FIXME: Turn into actual error.").parse().expect("FIXME");
+
+        assert!(a <= b);
+        
+        Ok(Self { a: a, b: b })
+    }
+}
+
+fn main() {
+    let stdin = std::io::stdin();
+    let handle = stdin.lock();
+
+    let mut count: usize = 0;
+    
+    for l in handle.lines() {
+        let line = l.unwrap();
+        let mut split = line.split(',');
+        let i_1 = split.next().unwrap().parse::<Interval<usize>>().unwrap();
+        let i_2 = split.next().unwrap().parse::<Interval<usize>>().unwrap();
+
+        if i_1 <= i_2 || i_1 >= i_2 {
+            count += 1;
+        }
+    }
+
+    println!("{}", count);
+}
diff --git a/04/src/part-2.rs b/04/src/part-2.rs
new file mode 100644
index 0000000..5c12d21
--- /dev/null
+++ b/04/src/part-2.rs
@@ -0,0 +1,71 @@
+use std::cmp::{Ordering, PartialOrd};
+use std::io::{BufRead};
+use std::str::FromStr;
+
+#[derive(Debug, Eq, PartialEq)]
+struct Interval {
+    a: usize,
+    b: usize
+}
+
+impl PartialOrd for Interval {
+    fn partial_cmp(self: & Self, other: & Self) -> Option<Ordering> {
+        if self == other {
+            Some(Ordering::Equal)
+        }
+        else if self.a >= other.a && self.b <= other.b {
+            Some(Ordering::Less)
+        }
+        else if self.a <= other.a && self.b >= other.b {
+            Some(Ordering::Greater)
+        }
+        else {
+            None
+        }
+    }
+}
+
+impl Interval {
+    fn overlaps(self: & Self, other : & Self) -> bool {
+        self == other
+            || self <= other
+            || self >= other
+            || (self.a <= other.a && self.b >= other.a)
+            || (self.b >= other.b && self.a <= other.b)
+    }
+    
+}
+
+impl FromStr for Interval {
+    type Err = std::string::ParseError;
+
+    fn from_str(s: & str) -> Result<Self, Self::Err> {
+        let mut split = s.split('-');
+        let a: usize = split.next().expect("FIXME: Turn into actual error.").parse().expect("FIXME");
+        let b: usize = split.next().expect("FIXME: Turn into actual error.").parse().expect("FIXME");
+
+        assert!(a <= b);
+        
+        Ok(Self { a: a, b: b })
+    }
+}
+
+fn main() {
+    let stdin = std::io::stdin();
+    let handle = stdin.lock();
+
+    let mut count: usize = 0;
+    
+    for l in handle.lines() {
+        let line = l.unwrap();
+        let mut split = line.split(',');
+        let i_1 = split.next().unwrap().parse::<Interval>().unwrap();
+        let i_2 = split.next().unwrap().parse::<Interval>().unwrap();
+
+        if i_1.overlaps(& i_2) {
+            count += 1;
+        }
+    }
+
+    println!("{}", count);
+}
diff --git a/04/test.txt b/04/test.txt
new file mode 100644
index 0000000..9f9e9cf
--- /dev/null
+++ b/04/test.txt
@@ -0,0 +1,6 @@
+2-4,6-8
+2-3,4-5
+5-7,7-9
+2-8,3-7
+6-6,4-6
+2-6,4-8
diff --git a/05/Cargo.toml b/05/Cargo.toml
new file mode 100644
index 0000000..6771697
--- /dev/null
+++ b/05/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+name = "day-05"
+version = "0.1.0"
+authors = ["Gard Spreemann <gspr@nonempty.org>"]
+edition = "2021"
+
+[[bin]]
+name = "part-1"
+path = "src/part-1.rs"
+
+[[bin]]
+name = "part-2"
+path = "src/part-2.rs"
+
+[dependencies]
diff --git a/05/input.txt b/05/input.txt
new file mode 100644
index 0000000..c6ab421
--- /dev/null
+++ b/05/input.txt
@@ -0,0 +1,513 @@
+[H]                 [Z]         [J]
+[L]     [W] [B]     [G]         [R]
+[R]     [G] [S]     [J] [H]     [Q]
+[F]     [N] [T] [J] [P] [R]     [F]
+[B]     [C] [M] [R] [Q] [F] [G] [P]
+[C] [D] [F] [D] [D] [D] [T] [M] [G]
+[J] [C] [J] [J] [C] [L] [Z] [V] [B]
+[M] [Z] [H] [P] [N] [W] [P] [L] [C]
+ 1   2   3   4   5   6   7   8   9 
+
+move 3 from 2 to 1
+move 8 from 6 to 4
+move 4 from 8 to 2
+move 3 from 1 to 9
+move 1 from 2 to 4
+move 3 from 7 to 5
+move 3 from 9 to 2
+move 3 from 3 to 5
+move 1 from 5 to 1
+move 5 from 1 to 8
+move 2 from 1 to 8
+move 3 from 7 to 3
+move 1 from 8 to 9
+move 6 from 9 to 8
+move 3 from 8 to 7
+move 7 from 8 to 9
+move 2 from 5 to 9
+move 2 from 2 to 9
+move 3 from 3 to 7
+move 2 from 8 to 3
+move 7 from 4 to 8
+move 3 from 4 to 1
+move 4 from 8 to 6
+move 4 from 6 to 1
+move 8 from 1 to 2
+move 1 from 1 to 4
+move 3 from 5 to 1
+move 8 from 9 to 8
+move 4 from 3 to 1
+move 5 from 5 to 3
+move 2 from 7 to 1
+move 1 from 7 to 4
+move 1 from 7 to 2
+move 3 from 3 to 5
+move 3 from 9 to 1
+move 9 from 8 to 1
+move 2 from 9 to 7
+move 1 from 8 to 5
+move 4 from 5 to 3
+move 1 from 3 to 4
+move 1 from 9 to 6
+move 1 from 6 to 9
+move 7 from 4 to 9
+move 1 from 7 to 3
+move 1 from 8 to 2
+move 8 from 2 to 1
+move 4 from 3 to 5
+move 2 from 9 to 6
+move 2 from 6 to 2
+move 2 from 4 to 9
+move 8 from 9 to 2
+move 3 from 7 to 9
+move 1 from 3 to 5
+move 2 from 3 to 8
+move 9 from 2 to 1
+move 1 from 8 to 7
+move 4 from 2 to 9
+move 4 from 5 to 6
+move 1 from 8 to 9
+move 27 from 1 to 2
+move 1 from 6 to 4
+move 3 from 6 to 4
+move 7 from 9 to 8
+move 4 from 4 to 1
+move 9 from 2 to 6
+move 2 from 1 to 9
+move 6 from 1 to 3
+move 1 from 5 to 3
+move 3 from 3 to 5
+move 3 from 5 to 3
+move 3 from 3 to 1
+move 4 from 6 to 7
+move 3 from 9 to 2
+move 1 from 6 to 4
+move 4 from 3 to 5
+move 3 from 6 to 5
+move 1 from 6 to 2
+move 15 from 2 to 3
+move 5 from 5 to 9
+move 13 from 3 to 9
+move 2 from 5 to 7
+move 1 from 4 to 2
+move 3 from 3 to 7
+move 11 from 2 to 7
+move 7 from 9 to 5
+move 3 from 5 to 7
+move 6 from 8 to 9
+move 4 from 1 to 2
+move 6 from 1 to 6
+move 3 from 5 to 1
+move 1 from 8 to 2
+move 4 from 2 to 9
+move 1 from 5 to 7
+move 6 from 7 to 6
+move 18 from 7 to 5
+move 1 from 7 to 1
+move 8 from 9 to 5
+move 1 from 2 to 6
+move 15 from 5 to 6
+move 6 from 5 to 3
+move 4 from 3 to 6
+move 26 from 6 to 5
+move 2 from 1 to 7
+move 4 from 5 to 9
+move 8 from 5 to 7
+move 3 from 7 to 9
+move 14 from 9 to 8
+move 7 from 5 to 2
+move 4 from 2 to 1
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+move 12 from 5 to 3
+move 5 from 8 to 5
+move 14 from 3 to 2
+move 1 from 5 to 2
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+move 7 from 9 to 6
+move 6 from 8 to 6
+move 1 from 2 to 7
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+move 1 from 5 to 9
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+move 1 from 4 to 2
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+move 7 from 7 to 2
+move 5 from 5 to 1
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+move 3 from 9 to 8
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+move 2 from 1 to 4
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+move 4 from 2 to 8
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+move 2 from 4 to 3
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+move 16 from 9 to 3
+move 16 from 3 to 2
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+move 1 from 9 to 3
+move 1 from 2 to 5
+move 1 from 9 to 4
+move 3 from 2 to 8
+move 1 from 9 to 1
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+move 7 from 3 to 1
+move 5 from 3 to 5
+move 3 from 8 to 3
+move 2 from 3 to 4
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+move 3 from 6 to 7
+move 3 from 8 to 9
+move 3 from 5 to 2
+move 3 from 1 to 3
+move 1 from 4 to 8
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+move 13 from 4 to 7
+move 14 from 6 to 7
+move 6 from 1 to 9
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+move 1 from 8 to 7
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+move 1 from 8 to 9
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+move 1 from 2 to 6
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+move 3 from 5 to 6
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+move 4 from 3 to 7
+move 14 from 7 to 3
+move 6 from 4 to 8
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+move 2 from 3 to 1
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+move 3 from 1 to 5
+move 2 from 5 to 7
+move 5 from 5 to 1
+move 8 from 7 to 4
+move 1 from 6 to 4
+move 1 from 7 to 4
+move 9 from 2 to 7
+move 8 from 7 to 6
+move 5 from 6 to 4
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+move 2 from 6 to 1
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+move 9 from 1 to 8
+move 9 from 6 to 2
+move 1 from 1 to 8
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+move 2 from 9 to 7
+move 2 from 7 to 9
+move 15 from 2 to 8
+move 18 from 4 to 2
+move 14 from 4 to 5
+move 10 from 2 to 4
+move 9 from 2 to 6
+move 1 from 9 to 3
+move 1 from 3 to 1
+move 6 from 5 to 8
+move 3 from 4 to 9
+move 2 from 2 to 1
+move 1 from 1 to 6
+move 3 from 9 to 7
+move 22 from 8 to 6
+move 1 from 8 to 9
+move 2 from 1 to 5
+move 5 from 5 to 4
+move 2 from 5 to 8
+move 2 from 8 to 7
+move 1 from 9 to 7
+move 1 from 5 to 8
+move 1 from 9 to 8
+move 15 from 6 to 4
+move 2 from 5 to 2
+move 11 from 4 to 6
+move 5 from 4 to 1
+move 5 from 4 to 2
+move 2 from 1 to 5
+move 6 from 2 to 8
+move 11 from 6 to 3
+move 12 from 6 to 8
+move 1 from 3 to 9
+move 3 from 3 to 2
+move 6 from 4 to 2
+move 2 from 5 to 8
+move 5 from 7 to 2
+move 11 from 8 to 4
+move 1 from 7 to 4
+move 1 from 9 to 6
+move 7 from 2 to 1
+move 3 from 6 to 5
+move 2 from 5 to 3
+move 1 from 5 to 9
+move 3 from 4 to 9
+move 4 from 9 to 1
+move 4 from 3 to 6
+move 3 from 4 to 8
+move 3 from 8 to 9
+move 2 from 8 to 2
+move 9 from 8 to 7
+move 2 from 3 to 1
+move 2 from 3 to 2
+move 1 from 3 to 6
+move 2 from 9 to 1
+move 8 from 7 to 5
+move 7 from 2 to 7
+move 2 from 8 to 9
+move 4 from 6 to 5
+move 13 from 1 to 5
+move 4 from 1 to 8
+move 3 from 9 to 3
+move 12 from 5 to 9
+move 3 from 8 to 9
+move 1 from 8 to 4
+move 3 from 2 to 7
+move 3 from 3 to 7
+move 1 from 9 to 2
+move 4 from 6 to 4
+move 6 from 5 to 6
+move 2 from 7 to 3
+move 2 from 2 to 1
+move 5 from 6 to 5
+move 1 from 1 to 7
+move 9 from 5 to 4
+move 10 from 9 to 6
+move 1 from 2 to 6
+move 12 from 7 to 6
+move 1 from 7 to 4
+move 23 from 6 to 1
+move 10 from 4 to 3
+move 16 from 1 to 5
+move 5 from 1 to 2
+move 6 from 3 to 7
+move 5 from 4 to 8
diff --git a/05/src/part-1.rs b/05/src/part-1.rs
new file mode 100644
index 0000000..b26d521
--- /dev/null
+++ b/05/src/part-1.rs
@@ -0,0 +1,82 @@
+mod stack;
+use stack::{Stack};
+
+use std::io::{BufRead};
+
+enum State {
+    Initial,
+    Skip,
+    Instructions
+}
+
+fn main() {    
+    let stdin = std::io::stdin();
+    let mut handle = stdin.lock();
+
+    let mut stacks: Vec<Stack<u8>> = Vec::new();
+    let mut state: State = State::Initial;
+    let mut initial_configuration: Vec<Vec<u8>> = Vec::new();
+    let mut buf: Vec<u8> = Vec::new();
+
+    loop {
+        buf.clear();
+        let num_bytes = handle.read_until(b'\n', &mut buf).expect("IO error");
+        if num_bytes == 0 { break; }
+
+        match state {
+            State::Initial => {
+                if buf.contains(& b'[') {
+                    initial_configuration.push(buf.clone());
+                }
+                else {
+                    state = State::Skip;
+                }
+            },
+            State::Skip => {
+                stacks = std::iter::repeat(Stack::new()).take(initial_configuration[0].len()/4).collect();
+                for line in (&initial_configuration).into_iter().rev() {
+                    for i in 0..stacks.len() {
+                        let x: u8 = line[4*i + 1];
+                        if x != b' ' {
+                            stacks[i].push(x);
+                        }
+                    }
+                    //println!("CFG: {}", line[5]);
+                }
+                state = State::Instructions;
+            },
+            State::Instructions => {
+                buf.pop(); // Drop newline.
+                let mut words = buf.split(|c| c == &b' ');
+                let w0 = words.next().expect("Malformed input");
+                let w1 = words.next().expect("Malformed input");
+                let w2 = words.next().expect("Malformed input");
+                let w3 = words.next().expect("Malformed input");
+                let w4 = words.next().expect("Malformed input");
+                let w5 = &words.next().expect("Malformed input");
+                assert_eq!(w0, b"move");
+                assert_eq!(w2, b"from");
+                assert_eq!(w4, b"to");
+                
+                let count: usize = std::str::from_utf8(w1).expect("Malformed input")
+                    .parse().expect("Malformed input");
+                let from: usize = std::str::from_utf8(w3).expect("Malformed input")
+                    .parse().expect("Malformed input");
+                let to: usize = std::str::from_utf8(w5).expect("Malformed input")
+                    .parse().expect("Malformed input");
+
+                for _ in 0..count {
+                    let x = stacks[from-1].pop().unwrap();
+                    stacks[to-1].push(x);
+                }
+            }
+        }
+    }
+
+
+    for stack in stacks {
+        let x: char = char::from(*stack.peek().unwrap());
+        print!("{}", x);
+    }
+    println!("");
+}
diff --git a/05/src/part-2.rs b/05/src/part-2.rs
new file mode 100644
index 0000000..9979f6f
--- /dev/null
+++ b/05/src/part-2.rs
@@ -0,0 +1,88 @@
+mod stack;
+use stack::{Stack};
+
+use std::io::{BufRead};
+
+enum State {
+    Initial,
+    Skip,
+    Instructions
+}
+
+fn main() {    
+    let stdin = std::io::stdin();
+    let mut handle = stdin.lock();
+
+    let mut stacks: Vec<Stack<u8>> = Vec::new();
+    let mut intermediate_stack: Stack<u8> = Stack::new();
+    let mut state: State = State::Initial;
+    let mut initial_configuration: Vec<Vec<u8>> = Vec::new();
+    let mut buf: Vec<u8> = Vec::new();
+
+    loop {
+        buf.clear();
+        let num_bytes = handle.read_until(b'\n', &mut buf).expect("IO error");
+        if num_bytes == 0 { break; }
+
+        match state {
+            State::Initial => {
+                if buf.contains(& b'[') {
+                    initial_configuration.push(buf.clone());
+                }
+                else {
+                    state = State::Skip;
+                }
+            },
+            State::Skip => {
+                stacks = std::iter::repeat(Stack::new()).take(initial_configuration[0].len()/4).collect();
+                for line in (&initial_configuration).into_iter().rev() {
+                    for i in 0..stacks.len() {
+                        let x: u8 = line[4*i + 1];
+                        if x != b' ' {
+                            stacks[i].push(x);
+                        }
+                    }
+                    //println!("CFG: {}", line[5]);
+                }
+                state = State::Instructions;
+            },
+            State::Instructions => {
+                buf.pop(); // Drop newline.
+                let mut words = buf.split(|c| c == &b' ');
+                let w0 = words.next().expect("Malformed input");
+                let w1 = words.next().expect("Malformed input");
+                let w2 = words.next().expect("Malformed input");
+                let w3 = words.next().expect("Malformed input");
+                let w4 = words.next().expect("Malformed input");
+                let w5 = &words.next().expect("Malformed input");
+                assert_eq!(w0, b"move");
+                assert_eq!(w2, b"from");
+                assert_eq!(w4, b"to");
+                
+                let count: usize = std::str::from_utf8(w1).expect("Malformed input")
+                    .parse().expect("Malformed input");
+                let from: usize = std::str::from_utf8(w3).expect("Malformed input")
+                    .parse().expect("Malformed input");
+                let to: usize = std::str::from_utf8(w5).expect("Malformed input")
+                    .parse().expect("Malformed input");
+
+                intermediate_stack.clear();
+                
+                for _ in 0..count {
+                    let x = stacks[from-1].pop().unwrap();
+                    intermediate_stack.push(x);
+                }
+                for _ in 0..count {
+                    stacks[to-1].push(intermediate_stack.pop().unwrap());
+                }
+            }
+        }
+    }
+
+
+    for stack in stacks {
+        let x: char = char::from(*stack.peek().unwrap());
+        print!("{}", x);
+    }
+    println!("");
+}
diff --git a/05/src/stack.rs b/05/src/stack.rs
new file mode 100644
index 0000000..ef42aab
--- /dev/null
+++ b/05/src/stack.rs
@@ -0,0 +1,28 @@
+#[derive(Clone)]
+pub struct Stack<T> {
+    data: Vec<T>
+}
+
+impl<T> Stack<T> {
+    pub fn new() -> Self {
+        Self {
+            data: Vec::new()
+        }
+    }
+
+    pub fn clear(self: &mut Self) {
+        self.data.clear();
+    }
+
+    pub fn push(self: &mut Self, x: T) {
+        self.data.push(x)
+    }
+
+    pub fn peek(self: & Self) -> Option<& T> {
+        self.data.last()
+    }
+
+    pub fn pop(self: &mut Self) -> Option<T> {
+        self.data.pop()
+    }
+}
diff --git a/05/test.txt b/05/test.txt
new file mode 100644
index 0000000..84933bb
--- /dev/null
+++ b/05/test.txt
@@ -0,0 +1,9 @@
+    [D]    
+[N] [C]    
+[Z] [M] [P]
+ 1   2   3 
+
+move 1 from 2 to 1
+move 3 from 1 to 3
+move 2 from 2 to 1
+move 1 from 1 to 2
diff --git a/06/Cargo.toml b/06/Cargo.toml
new file mode 100644
index 0000000..29ca8d8
--- /dev/null
+++ b/06/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+name = "day-06"
+version = "0.1.0"
+authors = ["Gard Spreemann <gspr@nonempty.org>"]
+edition = "2021"
+
+[[bin]]
+name = "part-1"
+path = "src/part-1.rs"
+
+[[bin]]
+name = "part-2"
+path = "src/part-2.rs"
+
+[dependencies]
diff --git a/06/input.txt b/06/input.txt
new file mode 100644
index 0000000..1db72f1
--- /dev/null
+++ b/06/input.txt
@@ -0,0 +1 @@
+cdhccdbdggfjjgssjzjzggjnjpnpbbzbnzzflfjfnfrrpvrvbrvvrvggvlvnnbrnrcncsnndbndbnndbdndfdrdvrvvndvvbggnrrnbrnntffgttwzwnnmvmcvvhsstzzlnlwlttbzzpnpmnnjvjnntmnmfftwwrfwrwswmmfrrfrrgbrbffwvvshvhrhmhththbbmqbmqqlslhssrmmqdmmjtmtmjtmjtttnwnvwvqwqjjnbbbdbqbnbpnbnllglcglcgcdczdznnqhhfthtmtlldqlqrrmddrldlzdllvddjcddqfqbqsbqqnllwppqpqzzrbbdppzsppjdpdqpdqdfqfrrwbwrwwqcqcsqsvvpbvbbztzptzzpccdtdhdffvqvcvzzmwzwddjfdffplplqlvlmmmvggpmpvpddpbptplpvlplvpvvnrvnnbqqqjhhwfhwfhwhqhmmpphqpqvppfzpzjzddgzzwffjmjggwhwwnnmlmpmmhcmcpcrcddvzvpzzwnznfznffgdgvddvtvgvsvdsdbbjnjtntbnttgbbbvgvgrgrzrvzrzddlsddcndcnnfqnnmpmlppdlplzplzpzgzmzmddlvlnnbttbwwhbhdhfdfssjppmcpplpdddnpdnnljlwjljsjnjhnhvhvqqsffrbbdttjdjndjdwwsfspffnhfhhlvhvmmqjmmwzwszwwvdvpdvdbdtdsdtsshvvmtvmtmctclchccrllznzfffpjjvhhdmhhvphpghgsgmmhlhnlnmnlnslnlgngznnsqnqddllpwllmzmjmttptfpplglqlgglgqqptqqmvmtmjmddcchbblltslsvsmvmgghmmccnzcztczzmnmttrdrvvcvzvvzllbhllnldndbbqffbbgtgddbtdbbzttdptpccjnjppbllbzlblrlcllhrrhqhgqqbcqcvcdvvnnzfzvzttrptrrwmrmlrlddvttdbtdbdcdvccwlcwwhphmppwfppclpcllgqgnghhvfflfggrzrcchfhhrdhrdhdnhnmmhjjwqjjpmmwvmmdnmnzzqmqwwmtthtdhtthnnqhqdhqqndqqwffsbspbptpmmndnllsmmdhmhfhnhjhghshlslppbgpgngddlsljsjmmzqzhhswhssfzssfqqcmqcmqcmmqggjcjvvgssrccwddmpmwwdfdpdbdpdwdvvqfvfrvvvsbvbhvvmqqcjqqvzqzppncnhhqnnpgplpqqpjpbblpbbbshsthhvfhfmmqzmmznnvrvqrrwdrdlrlwlttzqttjvttqltqqnfqqqwjqwwqttfstftjffsqqnhhnsnqqhggbsgghfgglslmssqlqhlhthqhccdsspsnssshbbnmngnnhllwclcffqllsrszrssnqsqvqjvjcvcttqgqbqmmfqfsqfsqswwvcvffndnfdfvfcvvggsmsfmfwfpfwwzhznntgtlglmmlfmllwrlrwwhcchqchhznzjjcdjdbjjhcjcscwwlnnsgngqqtgqgngnwgnnhqnnhchmchhtchcnclcmccgffbmmzvvrnngwwvddzccnjntjtwjwwztwtmtddjddpsptpbpbvvbwwnlnmndmnmdnnclnnbsbddpfdfvvjtjqqtqqqzjzlzqllzzwwlppvfffpcffffprrncnnzsnznhhwvvqhqphpjjgqqvnnmdmqqglqlblgglrlsspscsjjpvpbpjjwccslsppdjpdjjwvjjmhjhtjjwqqbqjqzjqzqpqbbswwlssqzssbjjpjqjbbjcjpjspjssjjzhhhnjhnhbnhhwzhzwlcshqlqpzgggzmcwntcwmfgtrwwjdpnbdqqcgnzgbdrzdmpwgvtvqffqbpvjpjrcfswffllnvnwvhclpjcwqwgnwqwvwsfgflrgzzsswffwjdjgvdvlgmczcbthwbvhggwzwlzfmhvwvjpbpnhcczbgfhhgghsmjwnvnsvnvmqwstrgnncwbqgbqpgdngllcqnzgwswpgtwzgqzggnzsdgltrlqfctqfvlzdswccfpdtjbfnrbqsmpjclnplbmqbmvwbzzdflwbqrljvzjpcrmnqsmrpqlmfsgcmthqpwgwzvmrjnhqczljcpnzjbwzrhjrzmcqpmlbzhgmqrlzsjbjsvcmcngptzlrthwsrjrlmsrgjlzrvpzwmprwnpgvjtspsppfvwfwcvbnqcwwmzlbqthqmbnbmnsnzgsbbnqtrvhlzjhphclpjzrdblszrnftqgwwrhpznhjhgrncvsvrmtmmgssvzddjfrnrzhbrqrfffjvzrqdnrdbvjwgrvlcpbncfgczlwdggsjmwzhndcdbggjvwfljctjnsjwczwfdrfttbhnlswfdbpcnwpspdhnzwqbgdswwpccbpfpgmfmvvwpzbzqsbbjbfnhjpszcbnrdplmwtdjtpcsztdjcmczltnstzwlcdbtdhsdgsgtlvdfqggfmmrppjfrmtfwhpbjsppszjbhmthndqmvbmqcbtqsltwrcvlvblwspbgspjftwllzcmnsrvjpnstzrfmcflnhppsdfggwbzvnvlnjqlfvrlplnzvfrwvgcgqvnpfgtgchctvhcplclzmfpwgnfhqjgglfmsgpflqcpqmbbhwnvvdllcnhblpnndbdtmgvfbvvvlvzlrpfqmnvzbfrssjtlgcjtpfznshvdjrjnfshfcgvwcdbqlfsbhnzwmsgwhpbzttgfjsqgwvdmbdwjljhsndrbbzfrsqjhcbldzqpmtnfvnmzltjcrvrltwshnhqlnclmcnfpbzstsczlqmfmdftzfbcwqnhqppzfbzpbfjhmmtvtbmblmtshsbtjlvsqvmbmgstbbdmhprqmtpfdqqntmnlbmpsmwfgrvstjcllhwpcddnljdjvdrbwqmgrjnldpgnrhgqpzqrvwzsngrgnbpjnsffzjsbdptwnnfcqlscfhvggpfstsnqzcjbqqhgdpqsrlprcppgqmddpqpbnvgwtdqsbbgtvsqfrtqfsbdzhsztfmvwrrsjcbtcjgzrnhnpgldtwbwgmwbgmjjzsbbzlhgmlczrhjwtzrgwscmjvlstprldhglvftqzbtrmcwzgtjppbnjcdvjvcwvdbngnbrmjvvtnwdqfclbpgzcfnnnlnngtgmhsqsdmbjctjzjpbrwrhscqshmmwbtfnzjgsrjlnqqdsvdrjdzsdprphnfmwwcztqfcrjvnfhlvnqwbrfmcvhrbtgvcrqjjfcnzwmlfzzdcbbzvphhmsdltwjfdcgthpvszqzjdbfwrpvhbjqdhrscnvjhjvvcldnhgjclmzpbrrwnscgpcqrpdgsnjnwhctcdqgwqbrcszfzpmtdrhlftvwffdjrtznqrppqbdbwvzmtlpvsqqpcngjgfdrpngnspdwhhvlhqrtsphgqrlldggtrvqsprbfdmrpgcmqphdvjfmhlznpgtqlvtnllcdhzhhtjjlfvdlwhcrfmjmdjtmbllvsfgvmfqtqlmrlrjmqptszvjdpzhphppljnpjdjpwlrclssgdnstchhwhpflmlrtdqvqbbljrmnflrltzpqmgqfrczvfzrpfsrwsgpljvjfjdjdvjchcdmmtjgghqspwzdtwqgtvmnrrbfbgnhcrvnzznrdlqmgmdwmpwzlqdjtvpszwnjtjtmjqvfwvftlhgpvgzswpbvbllfcwpjnsmbhzrdpdzjsrpnhphdcqjmzvvhrjcwhgwjwcshqwzpbpmfnjjvqcjrqmvsrdrtdvfhwhrbpvrqrsfzflslqtdrtcsggtzmpvbszdgttlvpwwltvpcwqmnwqtpcfzgsvsmncvpqqdrljfwtncplmjlpfcnqmcctwzhrbmrfwvsrjsbnhjrjmrnbmmnnhsvlltwzzhsgwppnlmljgpcsmpchdjdzpgvrtwsfzffhnlbfmrldzbshvpqhnfzpwnvczgfvhbntcpztwqlfgtsmdhvcrgjhvqrhbpvbpzcpbgzrcfjztbnfjptbzfpztwprwf
diff --git a/06/src/part-1.rs b/06/src/part-1.rs
new file mode 100644
index 0000000..14aaea5
--- /dev/null
+++ b/06/src/part-1.rs
@@ -0,0 +1,47 @@
+/*
+Just for fun, we'll try to pry out efficiency everywhere here:
+ - Don't do the convenient line iteration (causing allocations).
+ - Don't do UTF-8 allocation.
+ - Store seen characters in bitmap.
+ - TODO: There are probably some non-elided indexing safety checks.
+*/
+
+use std::io::{BufRead};
+
+const MARKER_LEN: usize = 4;
+
+fn count_ones<const N: usize>(xs: & [usize; N]) -> usize {
+    let mut ret: usize = 0;
+    for x in xs {
+        if *x == 1 { ret += 1; }
+    }
+    ret
+}
+
+fn main() {    
+    let stdin = std::io::stdin();
+    let mut handle = stdin.lock();
+    
+    let mut buf: Vec<u8> = Vec::new();
+      
+    loop {
+        buf.clear();
+        let num_bytes = handle.read_until(b'\n', &mut buf).expect("IO error");
+        if num_bytes == 0 { break; }
+        if buf.len() < MARKER_LEN { panic!("Malformed input"); }
+
+        let mut counts: [usize; 26] = [0; 26];
+        
+        for i in 0..buf.len() {
+            if i >= MARKER_LEN {
+                counts[(buf[i-MARKER_LEN] - b'a') as usize] -= 1;
+            }
+            counts[(buf[i] - b'a') as usize] += 1;
+            if count_ones(& counts) == MARKER_LEN {
+                println!("{}", i + 1);
+                break;
+            }
+        }
+    }
+    
+}
diff --git a/06/src/part-2.rs b/06/src/part-2.rs
new file mode 100644
index 0000000..8f004b0
--- /dev/null
+++ b/06/src/part-2.rs
@@ -0,0 +1,47 @@
+/*
+Just for fun, we'll try to pry out efficiency everywhere here:
+ - Don't do the convenient line iteration (causing allocations).
+ - Don't do UTF-8 allocation.
+ - Store seen characters in bitmap.
+ - TODO: There are probably some non-elided indexing safety checks.
+*/
+
+use std::io::{BufRead};
+
+const MARKER_LEN: usize = 14;
+
+fn count_ones<const N: usize>(xs: & [usize; N]) -> usize {
+    let mut ret: usize = 0;
+    for x in xs {
+        if *x == 1 { ret += 1; }
+    }
+    ret
+}
+
+fn main() {    
+    let stdin = std::io::stdin();
+    let mut handle = stdin.lock();
+    
+    let mut buf: Vec<u8> = Vec::new();
+      
+    loop {
+        buf.clear();
+        let num_bytes = handle.read_until(b'\n', &mut buf).expect("IO error");
+        if num_bytes == 0 { break; }
+        if buf.len() < MARKER_LEN { panic!("Malformed input"); }
+
+        let mut counts: [usize; 26] = [0; 26];
+        
+        for i in 0..buf.len() {
+            if i >= MARKER_LEN {
+                counts[(buf[i-MARKER_LEN] - b'a') as usize] -= 1;
+            }
+            counts[(buf[i] - b'a') as usize] += 1;
+            if count_ones(& counts) == MARKER_LEN {
+                println!("{}", i + 1);
+                break;
+            }
+        }
+    }
+    
+}
diff --git a/06/test-1.txt b/06/test-1.txt
new file mode 100644
index 0000000..3ef83c6
--- /dev/null
+++ b/06/test-1.txt
@@ -0,0 +1,5 @@
+mjqjpqmgbljsphdztnvjfqwrcgsmlb
+bvwbjplbgvbhsrlpgdmjqwftvncz
+nppdvjthqldpwncqszvftbrmjlhg
+nznrnfrfntjfmvfwmzdfjlvtqnbhcprsg
+zcfzfwzzqfrljwzlrfnpqdbhtmscgvjw
diff --git a/06/test-2.txt b/06/test-2.txt
new file mode 100644
index 0000000..3ef83c6
--- /dev/null
+++ b/06/test-2.txt
@@ -0,0 +1,5 @@
+mjqjpqmgbljsphdztnvjfqwrcgsmlb
+bvwbjplbgvbhsrlpgdmjqwftvncz
+nppdvjthqldpwncqszvftbrmjlhg
+nznrnfrfntjfmvfwmzdfjlvtqnbhcprsg
+zcfzfwzzqfrljwzlrfnpqdbhtmscgvjw