1 files changed, 88 insertions, 0 deletions
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!("");
+}