fn solve(_reader: R, _writer: &mut W) { let mut _scanner = Scanner::new(_reader); #[allow(unused_macros)] macro_rules! scan { ($t:ty) => { _scanner.next::<$t>().unwrap() }; ($($t:ty),+) => { ($(scan!($t)),+) }; ($t:ty; $n:expr) => { scan_iter!($t; $n).collect::>() }; ($t_0:ty, $t_1:ty; $n:expr) => { scan!($t_0 = 0, $t_1 = 1; $n) }; ($t_0:ty, $t_1:ty, $t_2:ty; $n:expr) => { scan!($t_0 = 0, $t_1 = 1, $t_2 = 2; $n) }; ($($t:ty = $i:tt),+; $n:expr) => {{ let mut vecs = ($(Vec::<$t>::with_capacity($n)),+); for _ in 0..$n {$( vecs.$i.push(scan!($t)); )+} vecs }}; } #[allow(unused_macros)] macro_rules! scan_iter { ($t:ty; $n:expr) => { _scanner.take::<$t>($n).map(|x| x.unwrap()) }; } #[allow(unused_macros)] macro_rules! print { ($fmt:expr) => { write!(_writer, $fmt).unwrap() }; ($fmt:expr, $($arg:tt)*) => { write!(_writer, $fmt, $($arg)*).unwrap() }; } #[allow(unused_macros)] macro_rules! println { () => { writeln!(_writer).unwrap() }; ($fmt:expr) => { writeln!(_writer, $fmt).unwrap() }; ($fmt:expr, $($arg:tt)*) => { writeln!(_writer, $fmt, $($arg)*).unwrap() }; } use std::collections::VecDeque; const DY: [isize; 4] = [0, 1, 0, -1]; const DX: [isize; 4] = [1, 0, -1, 0]; let (h, w) = scan!(usize, usize); let field = scan!(u8; h * w); let mut visited = vec![false; h * w]; let mut queue = VecDeque::<(isize, isize)>::new(); let (h, w) = (h as isize, w as isize); let index = |y, x| (y * w + x) as usize; let mut ans = 0; for i in 0..h { for j in 0..w { if field[index(i, j)] == b'1' && !visited[index(i, j)] { queue.push_back((i, j)); while let Some((y, x)) = queue.pop_front() { for (&dy, &dx) in DY.iter().zip(DX.iter()) { let y = y + dy; let x = x + dx; if 0 <= y && y < h && 0 <= x && x < w && field[index(y, x)] == b'1' { if !visited[index(y, x)] { visited[index(y, x)] = true; queue.push_back((y, x)); } } } } ans += 1; } } } println!("{}", ans); } fn main() { let stdin = stdin(); let stdout = stdout(); #[cfg(debug_assertions)] let mut writer = stdout.lock(); #[cfg(not(debug_assertions))] let mut writer = ::std::io::BufWriter::new(stdout.lock()); solve(stdin.lock(), &mut writer); writer.flush().unwrap(); } use io::Scanner; use std::io::{stdin, stdout, BufRead, Write}; pub mod io { pub use self::scanner::*; mod scanner { use std::io::BufRead; use std::marker::PhantomData; use std::str::{from_utf8, FromStr}; pub struct Scanner { reader: R, buffer: Vec, position: usize, } impl Scanner { pub fn new(reader: R) -> Self { Scanner { reader: reader, buffer: vec![], position: 0 } } pub fn next(&mut self) -> Option { Parse::parse(self.next_bytes().unwrap_or(&[])) } pub fn take(&mut self, n: usize) -> Take { Take { scanner: self, n: n, _marker: PhantomData } } pub fn next_bytes(&mut self) -> Option<&[u8]> { if self.buffer.is_empty() { self.read_line(); } loop { match self.buffer.get(self.position) { Some(&b' ') => self.position += 1, Some(&b'\n') => self.read_line(), Some(_) => break, None => return None, } } let start = self.position; loop { match self.buffer.get(self.position) { Some(&b' ') | Some(&b'\n') | None => break, Some(_) => self.position += 1, } } Some(&self.buffer[start..self.position]) } fn read_line(&mut self) { self.position = 0; self.buffer.clear(); self.reader.read_until(b'\n', &mut self.buffer).unwrap(); } } pub struct Take<'a, R: 'a, T> { scanner: &'a mut Scanner, n: usize, _marker: PhantomData T>, } impl<'a, R: BufRead, T: Parse> Iterator for Take<'a, R, T> { type Item = Option; fn next(&mut self) -> Option { if self.n > 0 { self.n -= 1; Some(self.scanner.next()) } else { None } } fn size_hint(&self) -> (usize, Option) { (self.n, Some(self.n)) } } impl<'a, R: BufRead, T: Parse> ExactSizeIterator for Take<'a, R, T> {} pub trait Parse: Sized { fn parse(bytes: &[u8]) -> Option; } impl Parse for u8 { fn parse(bytes: &[u8]) -> Option { if bytes.len() == 1 { Some(*unsafe { bytes.get_unchecked(0) }) } else { None } } } macro_rules! parse_impl { ($($t:ident)+) => {$( impl Parse for $t { fn parse(bytes: &[u8]) -> Option { from_utf8(bytes).ok().and_then(|s| $t::from_str(s).ok()) } } )+}; } parse_impl! { i32 i64 isize u32 u64 usize String } } }