From d85a0511dc5720824fcb05c94df02ec5fd769aa5 Mon Sep 17 00:00:00 2001
From: kleph <kleph@kleph.eu>
Date: Mon, 2 Dec 2024 01:04:46 +0100
Subject: [PATCH] 2024 - Day 1 part 2 - rust

---
 2024/rust1_2/.gitignore  |  2 ++
 2024/rust1_2/Cargo.toml  |  6 ++++++
 2024/rust1_2/src/main.rs | 34 ++++++++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+)
 create mode 100644 2024/rust1_2/.gitignore
 create mode 100644 2024/rust1_2/Cargo.toml
 create mode 100644 2024/rust1_2/src/main.rs

diff --git a/2024/rust1_2/.gitignore b/2024/rust1_2/.gitignore
new file mode 100644
index 0000000..a9d37c5
--- /dev/null
+++ b/2024/rust1_2/.gitignore
@@ -0,0 +1,2 @@
+target
+Cargo.lock
diff --git a/2024/rust1_2/Cargo.toml b/2024/rust1_2/Cargo.toml
new file mode 100644
index 0000000..d940546
--- /dev/null
+++ b/2024/rust1_2/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "rust1_2"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
diff --git a/2024/rust1_2/src/main.rs b/2024/rust1_2/src/main.rs
new file mode 100644
index 0000000..ff49d23
--- /dev/null
+++ b/2024/rust1_2/src/main.rs
@@ -0,0 +1,34 @@
+use std::io::{BufRead, BufReader};
+use std::fs::File;
+use std::collections::HashMap;
+
+fn main (){
+    // let filename = "../1/input_example.txt";
+    let filename = "../1/input.txt";
+    let file = BufReader::new(File::open(filename).expect("Unable to open file"));
+    let mut accum: u32 = 0;
+
+    let mut list1: Vec<u32> = vec![];
+    let mut counters: HashMap<u32, u32> = HashMap::new();
+
+    for line in file.lines() { 
+        let wline = line.unwrap();
+        let nums: Vec<&str> = wline.split(' ')
+            .filter(|&x| !x.is_empty())
+            .collect();
+
+        list1.push(nums[0].parse().unwrap());
+
+        counters.entry(nums[1].parse().unwrap())
+            .and_modify(|e| {*e += 1})
+            .or_insert(1);
+    }
+
+    for n in list1 {
+        if counters.contains_key(&n){
+            accum += n * counters[&n];
+        }
+    }
+
+    println!("{}", accum);
+}