#![allow(dead_code)] use std::env; use std::fs; use std::time::Instant; type Int = usize; fn substring_unique_copyless(s: &Vec, right: Int, length: Int) -> bool { for i in (right-length)..right { let c = s[i]; for j in (i+1)..right { if s[j] == c { return false; } } } return true; } fn find_first_unique_run(s: &Vec, num: Int, skip: Int) -> Int { for right in num.max(skip)..s.len() { if substring_unique_copyless(s, right, num) { return right; } } return 0; } fn mask_to_string(mask: u32) -> String { let mut v: Vec = Vec::with_capacity(mask.count_ones() as usize); for i in 0..26 { if mask & (1<) -> (Int, Int) { const BATCH_SIZE: Int = 8; const BATCH_NUM: Int = 4096/BATCH_SIZE; let mut four: Int = 0; let mut fourteen: Int = 0; let mut masks: [u32; 4096] = [0; 4096]; let mut scratch_masks: [u32; BATCH_SIZE] = [0; BATCH_SIZE]; let mut scratch_masks_bits: [u8; BATCH_SIZE] = [0; BATCH_SIZE]; for i in 0..4096 { masks[i] = 1 << (s[i]-b'a'); } // Turn masks into masks2. Indices are now +1. for i in 0..(4096-1) { masks[i] |= masks[i+1]; } 'four_loop: for batch in 1..(BATCH_NUM) { for i in 0..BATCH_SIZE { let idx = batch*BATCH_SIZE + i; scratch_masks[i] = masks[idx] | masks[idx-2]; scratch_masks_bits[i] = scratch_masks[i].count_ones() as u8; } for i in 0..BATCH_SIZE { if scratch_masks_bits[i] == 4 { four = batch*BATCH_SIZE + i; break 'four_loop; } } } // Turn masks2 into masks4. Indices are now +3. for i in four..(4096-3) { masks[i] |= masks[i+2]; } // Turn masks4 into masks8. Indices are now +7. for i in four..(4096-7) { masks[i] |= masks[i+4]; } 'fourteen_loop: for batch in (four/BATCH_SIZE)..(BATCH_NUM) { for i in 0..BATCH_SIZE { let idx = batch*BATCH_SIZE + i; // scratch_masks[i] = masks[idx] | masks[idx-4] | masks[idx-8] | masks[idx-10]; scratch_masks[i] = masks[idx] | masks[idx-6]; scratch_masks_bits[i] = scratch_masks[i].count_ones() as u8; } for i in 0..BATCH_SIZE { if scratch_masks_bits[i] == 14 { fourteen = batch*BATCH_SIZE + i; break 'fourteen_loop; } } } return (four+2, fourteen+8); } fn main() { let mut filename = "input/6"; let mut iterations = 1_000_000; let args: Vec = env::args().collect(); match args.len() { 3 => {filename = &args[1]; iterations = args[2].parse().expect(&("Invalid number for iterations: ".to_owned() + &args[2]))}, 2 => filename = &args[1], _ => (), }; let s: Vec = fs::read(filename).expect("Input not found!"); println!("Running {} iterations:", iterations); let t0 = Instant::now(); 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, fourteen) = find_first_unique_runs(&s); } let duration = t0.elapsed(); let per_iteration = duration / iterations; println!("Part 1: {}", four); println!("Part 2: {}", fourteen); println!("Completed {} iterations in {:.3}s (~{}ns each)", iterations, duration.as_secs_f32(), per_iteration.as_nanos()); }