From 928218226b4643b5e0b6cb491ed8af84bc0bd666 Mon Sep 17 00:00:00 2001
From: Siphalor <info@siphalor.de>
Date: Tue, 3 Dec 2024 23:31:21 +0100
Subject: [PATCH] Day one

---
 .gitignore               |  2 ++
 day-01-rust/.gitignore   |  1 +
 day-01-rust/Cargo.lock   |  7 +++++++
 day-01-rust/Cargo.toml   |  6 ++++++
 day-01-rust/src/main.rs  | 24 ++++++++++++++++++++++++
 day-01-rust/src/task1.rs | 27 +++++++++++++++++++++++++++
 day-01-rust/src/task2.rs | 31 +++++++++++++++++++++++++++++++
 7 files changed, 98 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 day-01-rust/.gitignore
 create mode 100644 day-01-rust/Cargo.lock
 create mode 100644 day-01-rust/Cargo.toml
 create mode 100644 day-01-rust/src/main.rs
 create mode 100644 day-01-rust/src/task1.rs
 create mode 100644 day-01-rust/src/task2.rs

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..607250b
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+input/
+.idea
diff --git a/day-01-rust/.gitignore b/day-01-rust/.gitignore
new file mode 100644
index 0000000..9f97022
--- /dev/null
+++ b/day-01-rust/.gitignore
@@ -0,0 +1 @@
+target/
\ No newline at end of file
diff --git a/day-01-rust/Cargo.lock b/day-01-rust/Cargo.lock
new file mode 100644
index 0000000..5756c5d
--- /dev/null
+++ b/day-01-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 = "day-01-rust"
+version = "0.1.0"
diff --git a/day-01-rust/Cargo.toml b/day-01-rust/Cargo.toml
new file mode 100644
index 0000000..a7230cc
--- /dev/null
+++ b/day-01-rust/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "day-01-rust"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
diff --git a/day-01-rust/src/main.rs b/day-01-rust/src/main.rs
new file mode 100644
index 0000000..0c91737
--- /dev/null
+++ b/day-01-rust/src/main.rs
@@ -0,0 +1,24 @@
+mod task1;
+mod task2;
+
+fn main() {
+    let args = std::env::args().collect::<Vec<_>>();
+    if args.len() != 3 {
+        println!("Usage: {} <1|2> <input file>", args[0]);
+        return;
+    }
+    let task = args.get(1).unwrap();
+    match task.as_str() {
+        "1" => {
+            task1::run(&*read_input(args.get(2).unwrap()));
+        }
+        "2" => {
+            task2::run(&*read_input(args.get(2).unwrap()));
+        }
+        _ => { eprintln!("First argument has to be 1 or 2") }
+    }
+}
+
+fn read_input(file: &str) -> String {
+    std::fs::read_to_string(file).expect("Could not read file")
+}
diff --git a/day-01-rust/src/task1.rs b/day-01-rust/src/task1.rs
new file mode 100644
index 0000000..ac00bf7
--- /dev/null
+++ b/day-01-rust/src/task1.rs
@@ -0,0 +1,27 @@
+use std::str::FromStr;
+
+pub fn run(input: &str) {
+    let mut first = Vec::<i64>::new();
+    let mut second = Vec::<i64>::new();
+    for line in input.split('\n') {
+        if let Some((first_part, second_part)) = line.split_once("   ") {
+            match i64::from_str(first_part) {
+                Ok(n) => first.push(n),
+                Err(err) => {
+                    eprintln!("Failed to parse first number from {}: {}", first_part, err);
+                }
+            }
+            match i64::from_str(second_part) {
+                Ok(n) => second.push(n),
+                Err(err) => {
+                    eprintln!("Failed to parse second number from {}: {}", second_part, err);
+                }
+            }
+        }
+    }
+
+    first.sort();
+    second.sort();
+    let sum = first.iter().zip(second.iter()).map(|(a, b)| a.abs_diff(*b)).sum::<u64>();
+    println!("Total difference: {}", sum);
+}
\ No newline at end of file
diff --git a/day-01-rust/src/task2.rs b/day-01-rust/src/task2.rs
new file mode 100644
index 0000000..1dfc7d2
--- /dev/null
+++ b/day-01-rust/src/task2.rs
@@ -0,0 +1,31 @@
+use std::collections::HashMap;
+use std::str::FromStr;
+
+pub fn run(input: &str) {
+    let mut first = Vec::<i64>::new();
+    let mut second = Vec::<i64>::new();
+    for line in input.split('\n') {
+        if let Some((first_part, second_part)) = line.split_once("   ") {
+            match i64::from_str(first_part) {
+                Ok(n) => first.push(n),
+                Err(err) => {
+                    eprintln!("Failed to parse first number from {}: {}", first_part, err);
+                }
+            }
+            match i64::from_str(second_part) {
+                Ok(n) => second.push(n),
+                Err(err) => {
+                    eprintln!("Failed to parse second number from {}: {}", second_part, err);
+                }
+            }
+        }
+    }
+
+    let mut second_counts = HashMap::<i64, i64>::new();
+    for element in second {
+        *second_counts.entry(element).or_insert(0) += 1;
+    }
+    
+    let result = first.iter().map(|num| num * second_counts.get(num).unwrap_or(&0)).sum::<i64>();
+    println!("Similarity: {}", result);
+}