day1

day1/src/main.rs

@@ -0,0 +1,156 @@
+use std::{fs::File, io::Read};
+
+fn main() {
+    let word_numbers: Vec<String> = vec![
+        String::from("zero"),
+        String::from("one"),
+        String::from("two"),
+        String::from("three"),
+        String::from("four"),
+        String::from("five"),
+        String::from("six"),
+        String::from("seven"),
+        String::from("eight"),
+        String::from("nine"),
+    ];
+    let data = get_data("data.txt");
+
+    let mut values: Vec<u32> = Vec::new();
+
+    for n in 0..data.len() {
+        let line = &data[n];
+
+        let digits = format!(
+            "{}{}",
+            get_first_digit(&word_numbers, line),
+            get_last_digit(&word_numbers, line)
+        );
+
+        let combined: u32 = match digits.parse() {
+            Ok(i) => i,
+            Err(err) => panic!("failed to parse digits: {} - {:?}", digits, err),
+        };
+
+        values.push(combined);
+    }
+
+    let total: u32 = values.iter().sum();
+
+    println!("## TOTAL: {} ##", total);
+}
+
+fn get_last_digit(word_numbers: &Vec<String>, line: &String) -> char {
+    if line.len() == 0 {
+        return '0';
+    }
+
+    let mut idx_word = 0;
+    let mut word: &String = &String::new();
+    for n in 0..word_numbers.len() {
+        let w = &word_numbers[n];
+        let mut is_match = false;
+
+        let idx = match line.rfind(&word_numbers[n]) {
+            Some(i) => {
+                is_match = true;
+                i
+            }
+            None => 0,
+        };
+
+        if is_match && idx >= idx_word {
+            idx_word = idx;
+            word = w;
+        }
+    }
+
+    let mut idx_char = line.len() - 1;
+    let mut digit: char = '0';
+    for c in line.chars().rev() {
+        if c.is_digit(10) {
+            digit = c;
+            break;
+        }
+
+        if idx_char > 0 {
+            idx_char -= 1;
+        }
+    }
+
+    if !word.is_empty() && idx_word >= idx_char {
+        return get_digit_from_str(word);
+    } else {
+        return digit;
+    }
+}
+
+fn get_first_digit(word_numbers: &Vec<String>, line: &String) -> char {
+    let mut idx_word = line.len();
+    let mut word: &String = &String::new();
+    for n in 0..word_numbers.len() {
+        let w = &word_numbers[n];
+
+        let idx = match line.find(&word_numbers[n]) {
+            Some(i) => i,
+            None => line.len(),
+        };
+
+        if idx < idx_word {
+            idx_word = idx;
+            word = w;
+        }
+    }
+
+    let mut idx_char = 0;
+    let mut digit: char = '0';
+    for c in line.chars() {
+        if c.is_digit(10) {
+            digit = c;
+            break;
+        }
+
+        idx_char += 1;
+    }
+
+    if idx_word == idx_char {
+        return '0';
+    }
+
+    if idx_word < idx_char {
+        return get_digit_from_str(word);
+    } else {
+        return digit;
+    }
+}
+
+fn get_data(path: &str) -> Vec<String> {
+    let mut data = match File::open(path) {
+        Ok(file) => file,
+        Err(err) => panic!("failed to read the data file: {:?}", err),
+    };
+
+    let mut content = String::new();
+    data.read_to_string(&mut content)
+        .ok()
+        .expect("failed to parse file");
+
+    let lines: Vec<String> = content.split("\n").map(|l| l.to_string()).collect();
+
+    return lines;
+}
+
+fn get_digit_from_str(word: &str) -> char {
+    match word {
+        "zero" => return '0',
+        "one" => return '1',
+        "two" => return '2',
+        "three" => return '3',
+        "four" => return '4',
+        "five" => return '5',
+        "six" => return '6',
+        "seven" => return '7',
+        "eight" => return '8',
+        "nine" => return '9',
+        _ => return '0',
+    }
+}