Added year directories for advent of code

advent_of_code/2021/d1/src/main.rs

@@ -0,0 +1,48 @@
+use std::io::{self, BufRead};
+use std::path::Path;
+use std::fs::File;
+
+fn main(){
+    println!("Advent of Code #1!");
+    println!();
+
+    let path = Path::new("./1.txt");
+    let display = path.display();
+
+    let file = match File::open(&path) {
+        Err(why) => panic!("Couldn't open {}: {}", display, why),
+        Ok(file) => file,
+    };
+
+    let lines = io::BufReader::new(file).lines();
+    let mut n = 0;
+    let mut prev = 0;
+    let mut line_vec = Vec::new();
+
+    for line in lines {
+        if let Ok(l) = line{
+            let i: u32 = l.parse().unwrap();
+            if i > prev {
+                n += 1;
+            }
+            prev = i;
+            line_vec.push(i);
+        }
+    }
+
+    println!("Number of increases: {}", n - 1);
+    println!();
+
+    prev = 0;
+    n = 0;
+
+    for i in 0..(line_vec.len() - 2) {
+        let sum = line_vec[i] + line_vec[i+1] + line_vec[i+2];
+        if sum > prev {
+            n += 1;
+        }
+        prev = sum;
+    }
+
+    println!("Number of increases with shifting window: {}", n - 1);
+}