attempt vectorization

2022/day6.rs

@@ -24,6 +24,49 @@ fn find_first_unique_run(s: &Vec<u8>, num: Int, skip: Int) -> Int {
 	return 0;
 }
 
+fn mask_to_string(mask: u32) -> String {
+	let mut v: Vec<u8> = Vec::with_capacity(mask.count_ones() as usize);
+	for i in 0..26 {
+		if mask & (1<<i) != 0 {
+			v.push(b'a'+i);
+		}
+	}
+	return String::from_utf8(v).unwrap();
+}
+
+fn find_first_unique_runs(s: &Vec<u8>) -> (Int, Int) {
+	let mut four = 0;
+	let mut fourteen = 0;
+	let mut masks: [u32; 4096] = [0; 4096];
+	for i in 0..s.len() {
+		masks[i] = 1 << (s[i]-b'a');
+	}
+	let mut m: [u32; 4096] = masks.clone();
+	for n in 1..4 {
+		for i in n..s.len() {
+			m[i] |= masks[i-n];
+		}
+	}
+	for i in 4..s.len() {
+		if m[i].count_ones() == 4 {
+			four = i;
+			break;
+		}
+	}
+	for n in 4..14 {
+		for i in n..s.len() {
+			m[i] |= masks[i-n];
+		}
+	}
+	for i in (four+9)..s.len() {
+		if m[i].count_ones() == 14 {
+			fourteen = i;
+			break;
+		}
+	}
+	return (four, fourteen);
+}
+
 fn run_once(s: &Vec<u8>) {
 	let four = find_first_unique_run(&s, 4, 0);
 	let fourteen = find_first_unique_run(&s, 14, four);
@@ -35,8 +78,9 @@ fn run_many(s: &Vec<u8>, iterations: usize) {
 	let mut four = 0;
 	let mut fourteen = 0;
 	for _ in 0..iterations {
-		four = find_first_unique_run(&s, 4, 0);
-		fourteen = find_first_unique_run(&s, 14, four);
+		// four = find_first_unique_run(&s, 4, 0);
+		// fourteen = find_first_unique_run(&s, 14, four);
+		(four, fourteen) = find_first_unique_runs(&s);
 	}
 	println!("Part 1: {}", four);
 	println!("Part 2: {}", fourteen);
@@ -45,6 +89,10 @@ fn run_many(s: &Vec<u8>, iterations: usize) {
 
 fn main() {
 	let input: Vec<u8> = fs::read("input/6").expect("Input not found!");
+	println!("Input is {} long", input.len());
 	// run_once(&input);
 	run_many(&input, 1_000_000);
+	// let (four, fourteen) = find_first_unique_runs(&input);
+	// println!("Part 1: {}", four);
+	// println!("Part 2: {}", fourteen);
 }