use proconio::{input, marker::Usize1}; fn main() { input! { h:usize, w:usize, a:[[usize;w];h], q:usize, query:[(Usize1,Usize1,Usize1,Usize1);q], } let mut poss = vec![vec![]; h * w + 1]; for i in 0..h { for j in 0..w { poss[a[i][j]].push(i * w + j); } } let mut rs = vec![(0, h * w); q]; while rs.iter().any(|&(l, r)| r - l > 1) { let mut ms = rs .iter() .enumerate() .map(|(i, &(l, r))| ((l + r) / 2, i)) .collect::>(); ms.sort(); let mut i = 0; let mut j = 0; let mut dsu = UnionFindTree::new(h * w); while i < q { while j <= ms[i].0 { for &pos in poss[j].iter() { for Pos { x: nx, y: ny } in Pos::new(pos / w, pos % w).neigh4(h, w) { if a[nx][ny] <= j { dsu.unite(pos, nx * w + ny); } } } j += 1; } let s = query[ms[i].1].0 * w + query[ms[i].1].1; let g = query[ms[i].1].2 * w + query[ms[i].1].3; if dsu.same(s, g) { rs[ms[i].1].1 = ms[i].0; } else { rs[ms[i].1].0 = ms[i].0; } i += 1; } } let ans = rs.into_iter().map(|(_, r)| r).collect::>(); for i in 0..q { println!("{}", ans[i]); } } use grid_mgr::*; mod grid_mgr { //[R,D,L,U] pub const DIR4: [(usize, usize); 4] = [(0, 1), (1, 0), (0, !0), (!0, 0)]; pub const DIR8: [(usize, usize); 8] = [ (1, 0), (1, !0), (0, !0), (!0, !0), (!0, 0), (!0, 1), (0, 1), (1, 1), ]; pub struct Pos { pub x: usize, pub y: usize, } impl Pos { #[allow(dead_code)] pub fn new(x: usize, y: usize) -> Self { Self { x, y } } #[allow(dead_code)] pub fn neigh4<'a>(&'a self, h: usize, w: usize) -> impl Iterator + 'a { DIR4.iter().filter_map(move |&(dx, dy)| { let nx = self.x.wrapping_add(dx); let ny = self.y.wrapping_add(dy); if nx < h && ny < w { Some(Pos::new(nx, ny)) } else { None } }) } #[allow(dead_code)] pub fn neigh8<'a>(&'a self, h: usize, w: usize) -> impl Iterator + 'a { DIR8.iter().filter_map(move |&(dx, dy)| { let nx = self.x.wrapping_add(dx); let ny = self.y.wrapping_add(dy); if nx < h && ny < w { Some(Pos::new(nx, ny)) } else { None } }) } #[allow(dead_code)] pub fn line<'a>( &'a self, h: usize, w: usize, dir: (usize, usize), ) -> impl Iterator + 'a { (0..).map_while(move |i| { let nx = self.x.wrapping_add(dir.0.wrapping_mul(i)); let ny = self.y.wrapping_add(dir.1.wrapping_mul(i)); if nx < h && ny < w { Some(Pos::new(nx, ny)) } else { None } }) } #[allow(dead_code)] pub fn _moveto(&self, h: usize, w: usize, dir: (usize, usize)) -> Option { let nx = self.x.wrapping_add(dir.0); let ny = self.y.wrapping_add(dir.1); if nx < h && ny < w { Some(Pos::new(nx, ny)) } else { None } } #[allow(dead_code)] pub fn moveto(&self, h: usize, w: usize, dir: char) -> Option { match dir { 'R' => self._moveto(h, w, DIR4[0]), 'D' => self._moveto(h, w, DIR4[1]), 'L' => self._moveto(h, w, DIR4[2]), 'U' => self._moveto(h, w, DIR4[3]), _ => unreachable!(), } } } } use unionfindtree::*; mod unionfindtree { pub struct UnionFindTree { par: Vec, rank: Vec, size: Vec, } impl UnionFindTree { pub fn new(n: usize) -> Self { Self { par: (0..n).collect::>(), rank: vec![0; n], size: vec![1; n], } } #[allow(dead_code)] pub fn same(&mut self, v1: usize, v2: usize) -> bool { self.root(v1) == self.root(v2) } #[allow(dead_code)] pub fn size(&mut self, v: usize) -> usize { let v_root = self.root(v); self.size[v_root] } #[allow(dead_code)] pub fn root(&mut self, v: usize) -> usize { if self.par[v] != v { self.par[v] = self.root(self.par[v]); } self.par[v] } pub fn unite(&mut self, v1: usize, v2: usize) { let mut v1_root = self.root(v1); let mut v2_root = self.root(v2); if v1_root == v2_root { return; } if self.rank[v1_root] < self.rank[v2_root] { std::mem::swap(&mut v1_root, &mut v2_root); } self.par[v2_root] = v1_root; self.size[v1_root] += self.size[v2_root]; if self.rank[v1_root] == self.rank[v2_root] { self.rank[v1_root] += 1; } } #[allow(dead_code)] pub fn nofcc(&mut self) -> usize { let n = self.par.len(); (0..n) .map(|v| self.root(v)) .collect::>() .len() } } }