Day Five

3 files changed, 79 insertions, 0 deletions

diff --git a/2022/rust/day05/Cargo.lock b/2022/rust/day05/Cargo.lock
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+++ b/2022/rust/day05/Cargo.lock
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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "day05"
+version = "0.1.0"
+dependencies = [
+ "text_io",
+]
+
+[[package]]
+name = "text_io"
+version = "0.1.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d5f0c8eb2ad70c12a6a69508f499b3051c924f4b1cfeae85bfad96e6bc5bba46"
diff --git a/2022/rust/day05/Cargo.toml b/2022/rust/day05/Cargo.toml
new file mode 100644
index 0000000..4cc1d88
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+++ b/2022/rust/day05/Cargo.toml
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+[package]
+name = "day05"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+text_io = "0.1.12"
diff --git a/2022/rust/day05/src/main.rs b/2022/rust/day05/src/main.rs
new file mode 100644
index 0000000..b13d16e
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+++ b/2022/rust/day05/src/main.rs
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+use std::collections::VecDeque;
+use std::env;
+use std::fs;
+use text_io::scan;
+
+fn main() {
+    let args = env::args().nth(1).expect("missing input");
+    let input = fs::read_to_string(args).unwrap();
+    let mut parts = input.split("\n\n");
+
+    let crates = parts.next().unwrap();
+    // yes, it's gross. yes, it works. no, i couldn't think of anything better.
+    let mut stacks: Vec<Vec<char>> = vec![];
+    for i in 0..9 {
+        let mut stack: Vec<char> = vec![];
+        for j in 0..8 {
+            stack.push(crates.chars().nth((9*4) * (7-j) + 4*i + 1).unwrap());
+        }
+        while *stack.last().unwrap() == ' ' {
+            stack.pop();
+        }
+        stacks.push(stack);
+    }
+
+    let instructions: Vec<[usize; 3]> = parts.next().unwrap().trim().split("\n").map(|x| {
+        let a: usize;
+        let b: usize;
+        let c: usize;
+        scan!(x.bytes() => "move {} from {} to {}", a, b, c);
+        return [a, b, c];
+    }).collect(); // collect() still messes me up
+    let capacity: usize = instructions.iter().fold(0, |x,y| x.max(y[0]));
+
+    let mut stack = stacks.clone();
+    for ins in &instructions {
+        for _ in 0 .. ins[0] {
+            let cargo = stack[ins[1]-1].pop().unwrap();
+            stack[ins[2]-1].push(cargo);
+        }
+    }
+    let answer: String = stack.iter().map(|x| x.last().unwrap()).collect();
+    println!("{}", answer);
+
+    let mut stack = stacks.clone();
+    for ins in instructions {
+        let mut cargo: VecDeque<char> = VecDeque::with_capacity(capacity);
+        for _ in 0 .. ins[0] {
+            cargo.push_front(stack[ins[1]-1].pop().unwrap());
+        }
+        stack[ins[2]-1].append(&mut cargo.into());
+    }
+    let answer: String = stack.iter().map(|x| x.last().unwrap()).collect();
+    println!("{}", answer);
+}