Add d1 in rust

Trying to learn more rust, so this is probably rusty.

.gitignore

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+target/

d01/Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "d01"
+version = "0.1.0"

d01/Cargo.toml

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+[package]
+name = "d01"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

d01/input_short.txt

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+199
+200
+208
+210
+200
+207
+240
+269
+260
+263

d01/src/main.rs

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+use std::collections::VecDeque;
+use std::fs::File;
+use std::io::{self, BufRead};
+use std::path::Path;
+
+fn read_lines<P>(filename: P) -> io::Result<io::Lines<io::BufReader<File>>>
+where
+    P: AsRef<Path>,
+{
+    let file = File::open(filename)?;
+    Ok(io::BufReader::new(file).lines())
+}
+
+fn part1() {
+    if let Ok(lines) = read_lines("input.txt") {
+        let mut last_val: Option<i32> = None;
+        let mut num_increase = 0;
+        for line in lines {
+            if let Ok(l) = line {
+                match l.parse::<i32>() {
+                    Ok(val) => {
+                        let increase;
+                        match last_val {
+                            Some(last_val) => increase = last_val < val,
+                            None => increase = false,
+                        }
+                        // println!("{}: {}", val, increase);
+                        if increase {
+                            num_increase += 1;
+                        }
+                        last_val = Some(val);
+                    }
+                    Err(e) => println!("ERROR: Could not parse {}. {}", l, e),
+                }
+            }
+        }
+
+        println!("Part 1, All done! Num increased {}", num_increase);
+    }
+}
+
+fn part2() {
+    if let Ok(lines) = read_lines("input.txt") {
+        let mut num_increase = 0;
+        // If we have 3 values, pop from front and compare new number to the one read before
+        // pushing that to the back. If that is an increase, increment the increase value
+        let mut sliding_values: VecDeque<i32> = VecDeque::with_capacity(3);
+        for line in lines {
+            if let Ok(l) = line {
+                match l.parse::<i32>() {
+                    Ok(val) => {
+                        if sliding_values.len() < 3 {
+                            sliding_values.push_back(val);
+                            continue;
+                        }
+                        let outgoing = sliding_values.pop_front().unwrap();
+                        let increase = val > outgoing;
+                        if increase {
+                            num_increase += 1;
+                        }
+                        sliding_values.push_back(val);
+                        println!("{}: {}", val, increase);
+                    }
+                    Err(e) => println!("ERROR: Could not parse {}. {}", l, e),
+                }
+            }
+        }
+
+        println!("All done! Num increased {}", num_increase);
+    }
+}
+
+fn main() {
+    part1();
+    part2();
+}