Solution for day 24 (part 1)

day24/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "day24"
+version = "0.1.0"
+authors = ["inga-lovinde <52715130+inga-lovinde@users.noreply.github.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

day24/src/main.rs

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+use std::collections::HashSet;
+use std::io::{self, BufRead};
+
+fn main() {
+    let stdin = io::stdin();
+    let mut changed_tiles = HashSet::new();
+    for line_result in stdin.lock().lines() {
+        let processed_line = line_result.unwrap().replace("nw", "7").replace("ne", "9").replace("sw", "1").replace("se", "3");
+        let mut x = 0;
+        let mut y = 0;
+        for ch in processed_line.chars() {
+            x += match ch {
+                'e' => 2,
+                'w' => -2,
+                '9' | '3' => 1,
+                '7' | '1' => -1,
+                _ => 0,
+            };
+            y += match ch {
+                '9' | '7' => 1,
+                '3' | '1' => -1,
+                _ => 0,
+            };
+        }
+
+        let tile = (x, y);
+        if changed_tiles.contains(&tile) {
+            changed_tiles.remove(&tile);
+        } else {
+            changed_tiles.insert(tile);
+        }
+    }
+
+    println!("{}", changed_tiles.len());
+}