From 3410d1f611ae9f019b271ed8b80ab34ddfc37e31 Mon Sep 17 00:00:00 2001
From: dobiadi <dobi@ktk.bme.hu>
Date: Sun, 3 Dec 2023 18:44:27 +0100
Subject: [PATCH] Day3 Rust

---
 day3/rust/.gitignore  |   1 +
 day3/rust/Cargo.lock  |   7 ++
 day3/rust/Cargo.toml  |   8 +++
 day3/rust/src/main.rs | 160 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 176 insertions(+)
 create mode 100644 day3/rust/.gitignore
 create mode 100644 day3/rust/Cargo.lock
 create mode 100644 day3/rust/Cargo.toml
 create mode 100644 day3/rust/src/main.rs

diff --git a/day3/rust/.gitignore b/day3/rust/.gitignore
new file mode 100644
index 0000000..eb5a316
--- /dev/null
+++ b/day3/rust/.gitignore
@@ -0,0 +1 @@
+target
diff --git a/day3/rust/Cargo.lock b/day3/rust/Cargo.lock
new file mode 100644
index 0000000..b21cc6a
--- /dev/null
+++ b/day3/rust/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "rust"
+version = "0.1.0"
diff --git a/day3/rust/Cargo.toml b/day3/rust/Cargo.toml
new file mode 100644
index 0000000..1ec6963
--- /dev/null
+++ b/day3/rust/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "rust"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/day3/rust/src/main.rs b/day3/rust/src/main.rs
new file mode 100644
index 0000000..b494390
--- /dev/null
+++ b/day3/rust/src/main.rs
@@ -0,0 +1,160 @@
+struct Number {
+    value: usize,
+}
+
+enum Symbol {
+    Asterisk,
+    Other,
+}
+
+enum Tile<'a> {
+    Number(&'a Number),
+    Symbol(Symbol),
+    Period,
+}
+
+fn main() {
+    let stdin = std::io::stdin();
+
+    let mut map: Vec<Vec<Tile>> = Vec::new();
+
+    for line in stdin.lines() {
+        let line = line.unwrap();
+
+        let mut num = Vec::new();
+        let mut v = Vec::new();
+        for char in line.chars() {
+            if !char.is_digit(10) && num.len() > 0 {
+                let s: String = num.iter().collect();
+
+                let number = Box::leak(Box::new(Number {
+                    value: s.parse().unwrap(),
+                }));
+
+                for _ in 0..s.len() {
+                    v.push(Tile::Number(number));
+                }
+
+                num.clear();
+            }
+
+            if char == '.' {
+                v.push(Tile::Period);
+            } else if char == '*' {
+                v.push(Tile::Symbol(Symbol::Asterisk));
+            } else if char.is_digit(10) {
+                num.push(char);
+            } else {
+                v.push(Tile::Symbol(Symbol::Other));
+            }
+        }
+
+        if num.len() > 0 {
+            let s: String = num.iter().collect();
+
+            let number = Box::leak(Box::new(Number {
+                value: s.parse().unwrap(),
+            }));
+
+            for _ in 0..s.len() {
+                v.push(Tile::Number(number));
+            }
+        }
+        map.push(v);
+    }
+
+    // Part 1
+    let mut part1 = 0;
+
+    for (x, row) in map.iter().enumerate() {
+        let mut already_added = false;
+        for (y, tile) in row.iter().enumerate() {
+            match tile {
+                Tile::Number(number) => {
+                    if already_added {
+                        continue;
+                    };
+
+                    for dx in -1i32..=1 {
+                        for dy in -1i32..=1 {
+                            let ix = x.wrapping_add(dx as usize);
+                            let iy = y.wrapping_add(dy as usize);
+                            if let Some(v) = map.get(ix) {
+                                if let Some(Tile::Symbol(_)) = v.get(iy) {
+                                    already_added = true;
+                                    part1 += number.value;
+                                }
+                            }
+                            if already_added {
+                                break;
+                            };
+                        }
+                        if already_added {
+                            break;
+                        };
+                    }
+                }
+                _ => {
+                    if already_added {
+                        already_added = false;
+                    }
+                }
+            }
+        }
+    }
+
+    println!("{}", part1);
+
+    // Part 2
+    let mut part2 = 0;
+
+    for (x, row) in map.iter().enumerate() {
+        for (y, tile) in row.iter().enumerate() {
+            if let Tile::Symbol(Symbol::Asterisk) = tile {
+                let mut gears = [None; 2];
+                let mut gear_num = 0;
+                let mut skip = false;
+
+                for dx in -1i32..=1 {
+                    for dy in -1i32..=1 {
+                        let ix = x.wrapping_add(dx as usize);
+                        let iy = y.wrapping_add(dy as usize);
+                        if let Some(v) = map.get(ix) {
+                            if let Some(Tile::Number(number)) = v.get(iy) {
+                                if let Some(gear) = gears[0] {
+                                    if std::ptr::eq(gear, *number) {
+                                        continue;
+                                    }
+                                }
+                                if let Some(gear) = gears[1] {
+                                    if std::ptr::eq(gear, *number) {
+                                        continue;
+                                    }
+                                }
+
+                                if gear_num == 2 {
+                                    skip = true;
+                                    break;
+                                }
+
+                                gears[gear_num] = Some(*number);
+                                gear_num += 1;
+                            }
+                        }
+                    }
+                    if skip {
+                        break;
+                    }
+                }
+
+                if gear_num == 2 {
+                    unsafe {
+                        part2 += (*gears[0].unwrap()).value * (*gears[1].unwrap()).value;
+                    }
+                }
+            }
+        }
+    }
+
+    println!("{}", part2);
+}