Port day03 part1 to rust

rust-rewrite/day03/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "day03"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

rust-rewrite/day03/src/main.rs

@@ -0,0 +1,55 @@
+use std::fs;
+
+fn main() {
+    let file = fs::read_to_string("day03.in").unwrap();
+    let data = ingest_data(file);
+    println!("=== PART 1 ===");
+    part1(&data);
+    println!("=== PART 2 ===");
+}
+
+fn ingest_data(input: String) -> Vec<String> {
+    let mut data: Vec<String> = vec![];
+    for line in input.strip_suffix('\n').unwrap().split('\n') {
+        data.push(line.to_string());
+    }
+    data
+}
+
+fn common_bit(data: &Vec<String>, bit: usize, invert: bool) -> char {
+    let mut bit_count = (0, 0);
+    for x in data {
+        match x.chars().nth(bit).unwrap() {
+            '0' => bit_count.0 += 1,
+            '1' => bit_count.1 += 1,
+            _ => (),
+        }
+    }
+    if bit_count.0 <= bit_count.1 {
+        if invert {
+            '0'
+        } else {
+            '1'
+        }
+    } else {
+        if invert {
+            '1'
+        } else {
+            '0'
+        }
+    }
+}
+
+fn part1(data: &Vec<String>) {
+    let mut gamma: String = "".to_string();
+    let mut epsilon: String = "".to_string();
+    for bit in 0..data[0].len() {
+        gamma.push(common_bit(data, bit, false));
+        epsilon.push(common_bit(data, bit, true));
+    }
+    let gamma_i = usize::from_str_radix(&gamma, 2).unwrap();
+    let epsilon_i = usize::from_str_radix(&epsilon, 2).unwrap();
+    println!("Gamma: {}", gamma_i);
+    println!("Epsilon: {}", epsilon_i);
+    println!("Power consumption: {}", gamma_i * epsilon_i);
+}