2023-01: Implement part 2

2023/01-trebuchet/src/main.rs

@@ -1,6 +1,7 @@
 mod part_one;
+mod part_two;
 
 fn main() {
-    part_one::part_one();
-    //part_two();
+    //part_one::part_one();
+    part_two::part_two();
 }

2023/01-trebuchet/src/part_two.rs

@@ -0,0 +1,73 @@
+use std::collections::HashMap;
+use std::fs::File;
+use std::io::{self, BufRead};
+use std::path::Path;
+
+
+pub fn part_two() {
+    if let Ok(lines) = read_lines("./input.txt") {
+
+        let mut result = 0;
+
+        for line in lines {
+            result += parse_line(&line.unwrap());
+        }
+
+        println!("{}", result);
+    }
+}
+
+fn read_lines<P>(filename: P) -> io::Result<io::Lines<io::BufReader<File>>>
+where P: AsRef<Path>, {
+    let file = File::open(filename)?;
+    Ok(io::BufReader::new(file).lines())
+}
+
+fn parse_line(s: &str) -> u32{
+
+    const RADIX: u32 = 10;
+
+    let digits : HashMap<&str, u32> = HashMap::from([
+        ("one", 1),
+        ("two", 2),
+        ("three", 3),
+        ("four", 4),
+        ("five", 5),
+        ("six", 6),
+        ("seven", 7),
+        ("eight", 8),
+        ("nine", 9),
+    ]);
+    
+    let mut first_digit = 0;
+    let mut last_digit = 0;
+
+    for i in 0..s.len() {
+
+        let c = s.chars().nth(i).unwrap();
+
+        if c.is_digit(RADIX) {
+
+            let digit = c.to_digit(RADIX).unwrap();
+
+            if first_digit == 0 {
+                first_digit = digit;
+            }
+            last_digit = digit;            
+        } else {
+
+            for (k, v) in digits.iter() {
+                if s[i..].starts_with(k) {
+
+                    if first_digit == 0 {
+                        first_digit = *v;
+                    }
+                    last_digit = *v;
+                }
+            }
+
+        }
+    }
+    
+    return first_digit * 10 + last_digit   
+}