Completed: 1, 2, 3, 4, 5.1, 6.1, 7, 8

day_01/src/main.rs

@@ -0,0 +1,80 @@
+use std::fs;
+
+fn main() {
+	// for _ in 0..1000 {
+	// 	a();
+	// }
+	a();
+	b();
+}
+
+fn a() {
+	/*
+	let data = include_str!("../1.txt");
+	let sum: i32 = data
+		.lines()
+		.map(|line| {
+			let nums: Vec<_> = line.chars().filter(|c| c.is_numeric()).collect();
+			let mut num = nums[0].to_string();
+			num.push(*nums.last().unwrap());
+			num.parse::<i32>().unwrap()
+		})
+		.sum();
+	println!("{sum:?}");
+	*/
+
+	let bytes = fs::read("input.txt").expect("input.txt not found");
+	let mut sum = 0;
+	let mut first_digit = 0;
+	let mut last_digit = 0;
+	for byte in bytes {
+		if byte <= b'9' && byte > b'0' {
+			let digit = byte - 48;
+			last_digit = digit;
+			if first_digit == 0 {
+				first_digit = digit * 10;
+			}
+		} else if byte == b'\n' {
+			sum += last_digit as u16;
+			sum += first_digit as u16;
+			last_digit = 0;
+			first_digit = 0;
+		}
+	}
+	println!("{sum}");
+}
+
+fn b() {
+	let data = include_str!("../1.txt");
+
+	let sum: i32 = data
+		.lines()
+		.map(|line| {
+			let mut digits = Vec::new();
+			for i in 0..line.len() {
+				let c = line.chars().nth(i).unwrap();
+				if c.is_numeric() {
+					digits.push(c);
+				} else {
+					for (digit, &text) in [
+						"one", "two", "three", "four", "five", "six", "seven", "eight", "nine",
+					]
+					.iter()
+					.enumerate()
+					.map(|(i, t)| ((i + 1).to_string().chars().next().unwrap(), t))
+					{
+						if line[i..].starts_with(text) {
+							digits.push(digit);
+							break;
+						}
+					}
+				}
+			}
+
+			let mut num = digits[0].to_string();
+			num.push(*digits.last().unwrap());
+			num.parse::<i32>().unwrap()
+		})
+		.sum();
+	println!("{sum:?}");
+}