use std::io; use std::collections::VecDeque; fn hash(input: &str, output: &mut[u8]) { let mut buffer = [0u8; 256]; for i in {0..256} { buffer[i] = i as u8; } let mut actual_key = String::from(input); // Needed to convert to hex actual_key += "\x11\x1f\x49\x2f\x17"; let mut index = 0u8; let mut skip = 0u8; for _ in 0..64 { for c in actual_key.chars() { let offset = c as u8; for i in 0..(offset / 2) { let i1 = index.wrapping_add(i) as usize; let i2 = index.wrapping_add(offset).wrapping_sub(i).wrapping_sub(1) as usize; let temp = buffer[i1]; buffer[i1] = buffer[i2]; buffer[i2] = temp; } index = index.wrapping_add(offset).wrapping_add(skip); skip = skip.wrapping_add(1); } } for (i, b) in buffer.iter().enumerate() { output[i / 16] ^= b; } } fn count_ones(input: &[[u8; 16]]) -> u32 { let mut total: u32 = 0; for row in input { let row_total: u32 = row.iter().map(|x| x.count_ones()).sum(); total += row_total; } return total; } fn get_hash(input: &str) -> [[u8; 16]; 128] { let mut hash_buffer = [[0u8; 16]; 128]; for i in 0..128 { let mut hash_key = String::from(input); hash_key += "-"; hash_key += &i.to_string(); hash(&hash_key, &mut hash_buffer[i]); } return hash_buffer; } fn is_used(hashes: &[[u8; 16]], y: usize, x: usize) -> bool { let byte = hashes[y][x / 8]; return (byte & (1 << (7 - (x % 8)))) != 0; } fn count_groups(hashes: &[[u8; 16]]) -> u32 { let mut visited = [[false; 128]; 128]; let mut groups = 0u32; for x in 0..128 { for y in 0..128 { if visited[x][y] || !is_used(hashes, x, y) { continue; } visited[x][y] = true; groups += 1; let mut todo = VecDeque::new(); todo.push_back((x, y)); while !todo.is_empty() { let (cur_x, cur_y) = todo.pop_front().unwrap(); let x_min = if cur_x == 0 { 0 } else { cur_x - 1 }; let y_min = if cur_y == 0 { 0 } else { cur_y - 1 }; let x_max = if cur_x == 127 { 128 } else { cur_x + 2 }; let y_max = if cur_y == 127 { 128 } else { cur_y + 2 }; for x_new in x_min..(x_max) { for y_new in y_min..(y_max) { if (cur_x != x_new) ^ (cur_y != y_new) && !visited[x_new][y_new] && is_used(hashes, x_new, y_new) { visited[x_new][y_new] = true; todo.push_back((x_new, y_new)); } } } } } } return groups; } fn main() { let reader = io::stdin(); let mut input = String::new(); reader.read_line(&mut input).unwrap(); let hashes = get_hash(input.trim()); println!("Part 1: {}", count_ones(&hashes)); println!("Part 2: {}", count_groups(&hashes)); }