day 5

day5/src/main.rs

@@ -0,0 +1,75 @@
+fn print_stacks(stacks: &Vec<Vec<char>>) {
+    for stack in stacks {
+        println!("{:?}", stack);
+    }
+}
+
+fn stacks_message(stacks: &Vec<Vec<char>>) -> String {
+    stacks.iter().map(|v| {
+        v[v.len() - 1]
+    }).fold(String::new(), |mut s, c| {
+        s.push(c);
+        s
+    })
+}
+
+fn main() {
+    const INPUT: &str = include_str!("../input.txt");
+    let chunks = INPUT.split_once("\n\n").unwrap();
+    
+    let mut stack_lines: Vec<String> = chunks.0.lines().map(|x| -> String {
+        x.to_string() + " "
+    }).collect();
+    stack_lines.pop();
+    let num_stacks = (stack_lines[0].len() + 1) / 4;
+
+    let mut stacks: Vec<Vec<char>> = vec![Vec::<char>::new(); num_stacks];
+
+    for line in stack_lines.iter().rev() {
+        let mut line = line.to_string();
+        line += " ";
+
+        for i in 0..num_stacks {
+            let c = line.chars().nth(i*4 + 1).unwrap();
+            if c.is_whitespace() {
+                continue;
+            }
+            
+            stacks[i].push(c);
+        }
+    }
+
+    let stacks_copy = stacks.clone();
+
+    let move_lines = chunks.1.lines();
+    for line in move_lines {
+        let split: Vec<&str> = line.split(" ").collect();
+        let n: usize = split[1].parse().unwrap();
+        let from = split[3].parse::<usize>().unwrap() - 1;
+        let to = split[5].parse::<usize>().unwrap() - 1;
+
+        for _ in 0..n {
+            let x = stacks[from].pop().unwrap();
+            stacks[to].push(x);
+        }
+    }
+
+    print_stacks(&stacks);
+    println!("Message: {}\n", stacks_message(&stacks));
+
+    let mut stacks = stacks_copy;
+    let move_lines = chunks.1.lines();
+    for line in move_lines {
+        let split: Vec<&str> = line.split(" ").collect();
+        let n: usize = split[1].parse().unwrap();
+        let from = split[3].parse::<usize>().unwrap() - 1;
+        let to = split[5].parse::<usize>().unwrap() - 1;
+
+        let len = stacks[from].len();
+        let mut x: Vec<char> = stacks[from].drain(len-n..len).collect();
+        stacks[to].append(x.as_mut());
+    }
+
+    print_stacks(&stacks);
+    println!("Message: {}", stacks_message(&stacks));
+}