// ---------- begin Lowest Common Ancestor ---------- struct LCA { graph: Vec>, path_root: Vec, path_parent: Vec, index: Vec } impl LCA { fn new(n: usize) -> Self { LCA { graph: vec![vec![]; n], path_root: vec![], path_parent: vec![], index: vec![], } } fn add_edge(&mut self, a: usize, b: usize) { self.graph[a].push(b); self.graph[b].push(a); } fn build(&mut self, root: usize) { let mut q = vec![]; let mut stack = vec![(root, root)]; let graph = &mut self.graph; while let Some((v, p)) = stack.pop() { q.push(v); for i in 0..graph[v].len() { if graph[v][i] == p { graph[v].swap_remove(i); break; } } for &u in &graph[v] { stack.push((u, v)); } } let n = graph.len(); let mut size = vec![1; n]; for &v in q.iter().rev() { for i in 0..graph[v].len() { let u = graph[v][i]; size[v] += size[u]; if size[u] > size[graph[v][0]] { graph[v].swap(0, i); } } } let mut path_root = vec![root; n]; let mut path_parent = vec![root; n]; let mut index = vec![n; n]; let mut stack = vec![root]; let mut k = 0; while let Some(v) = stack.pop() { index[v] = k; k += 1; for i in 1..graph[v].len() { let u = graph[v][i]; path_root[u] = u; path_parent[u] = v; stack.push(u); } if graph[v].len() > 0 { let u = graph[v][0]; path_root[u] = path_root[v]; path_parent[u] = path_parent[v]; stack.push(u); } } self.path_root = path_root; self.path_parent = path_parent; self.index = index; } fn query(&self, mut a: usize, mut b: usize) -> usize { let path = &self.path_root; let parent = &self.path_parent; let index = &self.index; while path[a] != path[b] { if index[a] < index[b] { b = parent[b]; } else { a = parent[a]; } } if index[a] < index[b] {a} else {b} } } // ---------- end Lowest Common Ancestor ---------- //---------- begin union_find ---------- #[allow(dead_code)] mod union_find { pub struct UF { p: Vec, } impl UF { pub fn new(n: usize) -> UF { UF {p: vec![-1; n] } } pub fn init(&mut self) { for p in self.p.iter_mut() { *p = -1; } } pub fn root(&self, mut x: usize) -> usize { while self.p[x] >= 0 { x = self.p[x] as usize; } x } pub fn same(&self, x: usize, y: usize) -> bool { self.root(x) == self.root(y) } pub fn unite(&mut self, mut x: usize, mut y: usize) -> Option<(usize, usize)> { x = self.root(x); y = self.root(y); if x == y { return None; } if self.p[x] > self.p[y] { let s = x; x = y; y = s; } self.p[x] += self.p[y]; self.p[y] = x as i32; Some((x, y)) } pub fn get_size(&mut self, x: usize) -> usize { let r = self.root(x); (-self.p[r]) as usize } } } //---------- end union_find ---------- use std::io::Read; fn run() { let mut s = String::new(); std::io::stdin().read_to_string(&mut s).unwrap(); let mut it = s.trim().split_whitespace(); let n: usize = it.next().unwrap().parse().unwrap(); let m: usize = it.next().unwrap().parse().unwrap(); let query: usize = it.next().unwrap().parse().unwrap(); let mut g = vec![vec![]; n + 1]; let mut u = union_find::UF::new(n + 1); let mut lca = LCA::new(n + 1); for _ in 0..m { let a: usize = it.next().unwrap().parse().unwrap(); let b: usize = it.next().unwrap().parse().unwrap(); g[a].push(b); g[b].push(a); lca.add_edge(a, b); u.unite(a, b); } let u = u; for i in 1..=n { if i == u.root(i) { g[0].push(i); lca.add_edge(0, i); } } lca.build(0); let mut q = vec![]; let mut stack = vec![(0, 0)]; let mut depth = vec![0; n + 1]; while let Some((v, p)) = stack.pop() { q.push(v); for i in 0..g[v].len() { if g[v][i] == p { g[v].remove(i); break; } } for &u in &g[v] { depth[u] = depth[v] + 1; stack.push((u, v)); } } let mut cnt = vec![0; n + 1]; let mut ans = 0usize; for _ in 0..query { let a: usize = it.next().unwrap().parse().unwrap(); let b: usize = it.next().unwrap().parse().unwrap(); if u.same(a, b) { ans += depth[a] + depth[b] - 2 * depth[lca.query(a, b)]; } else { cnt[a] += 1; cnt[b] += 1; } } let mut down = vec![0; n + 1]; let mut size = cnt.clone(); for &v in q[1..].iter().rev() { for &u in &g[v] { down[v] += down[u] + size[u]; size[v] += size[u]; } } let mut dp = down.clone(); let all_size = size.clone(); for &v in &q[1..] { let r = u.root(v); let d = dp[v]; for &u in &g[v] { dp[u] = d - size[u] + all_size[r] - size[u]; } } for v in 1..=n { let r = u.root(v); dp[r] = std::cmp::min(dp[r], dp[v]); } for v in 1..=n { if u.root(v) == v { ans += dp[v]; } } println!("{}", ans); } fn main() { run(); }