use std::io::stdin; #[derive(Clone, Copy, Debug, PartialEq, Eq)] struct Color(usize); #[derive(Clone, Copy, Debug, PartialEq, Eq)] struct Edge { u: usize, v: usize, } struct Problem { nv: usize, ne: usize, vertex_to_color: Vec, edges: Vec, } fn connected_component(nv: usize, edges: &[Edge]) -> i64 { let mut uf = UnionFind::new(nv); for &Edge { u, v } in edges { uf.unite(u, v); } uf.num_groups() as i64 } impl Problem { fn read(mut r: R) -> Problem { let (nv, ne) = r.read_usize_2(); let vertex_to_color = r.read_vec_i64().iter().copied().map(|c| Color(c as usize - 1)).collect(); let edges = (0..ne) .map(|_| { let (u, v) = r.read_usize_2(); let u = u - 1; let v = v - 1; Edge { u, v } }) .collect(); Problem { nv, ne, vertex_to_color, edges } } fn solve(&self) -> Answer { // itertools がほしい // 辺を色で分ける。 let mut color_to_vertex_list = vec![vec![]; self.nv]; for (v, color) in self.vertex_to_color.iter().copied().enumerate() { color_to_vertex_list[color.0].push(v); } //色ごとにグラフを作る let mut color_to_edge_list = vec![vec![]; self.nv]; for &e in &self.edges { if (self.vertex_to_color[e.u] == self.vertex_to_color[e.v]) { color_to_edge_list[self.vertex_to_color[e.u].0].push(e); } } let ans = (0..self.nv) .map(|color| { // 連結成分数を求める let edge_list = &color_to_edge_list[color]; let vertex_list = &color_to_vertex_list[color]; let cnt = connected_component(self.nv, edge_list); let cnt = cnt - (self.nv - vertex_list.len()) as i64; if cnt == 0 || cnt == 1 { 0 } else { cnt - 1 } }) .sum::(); Answer { ans } } } #[derive(Clone, Debug, PartialEq, Eq)] struct Answer { ans: i64, } impl Answer { fn print(&self) { println!("{}", self.ans); } } fn main() { Problem::read(ProconReader::new(stdin().lock())).solve().print(); } #[cfg(test)] mod tests { use super::*; #[allow(dead_code)] fn check(input: &str, expected: Answer) { let actual = Problem::read(ProconReader::new(input.as_bytes())).solve(); assert_eq!(expected, actual); } #[test] fn test_problem() { let _input = " 3 4 " .trim(); // check(_input, Answer { ans: 7 }); } } // ====== snippet ====== #[allow(unused_imports)] use myio::*; pub mod myio { use std::io::BufRead; pub trait IProconReader { fn read_line(&mut self) -> String; fn read_bytes(&mut self) -> Vec { self.read_line().as_bytes().to_vec() } fn read_any_1(&mut self) -> T where T: std::str::FromStr, T::Err: std::fmt::Debug, { let buf = self.read_line(); buf.parse::().unwrap() } fn read_any_2(&mut self) -> (T0, T1) where T0: std::str::FromStr, T0::Err: std::fmt::Debug, T1: std::str::FromStr, T1::Err: std::fmt::Debug, { let buf = self.read_line(); let splitted = buf.trim().split(' ').collect::>(); let a0 = splitted[0].parse::().unwrap(); let a1 = splitted[1].parse::().unwrap(); (a0, a1) } fn read_any_3(&mut self) -> (T0, T1, T2) where T0: std::str::FromStr, T0::Err: std::fmt::Debug, T1: std::str::FromStr, T1::Err: std::fmt::Debug, T2: std::str::FromStr, T2::Err: std::fmt::Debug, { let buf = self.read_line(); let splitted = buf.trim().split(' ').collect::>(); let a0 = splitted[0].parse::().unwrap(); let a1 = splitted[1].parse::().unwrap(); let a2 = splitted[2].parse::().unwrap(); (a0, a1, a2) } fn read_any_4(&mut self) -> (T0, T1, T2, T3) where T0: std::str::FromStr, T0::Err: std::fmt::Debug, T1: std::str::FromStr, T1::Err: std::fmt::Debug, T2: std::str::FromStr, T2::Err: std::fmt::Debug, T3: std::str::FromStr, T3::Err: std::fmt::Debug, { let buf = self.read_line(); let splitted = buf.trim().split(' ').collect::>(); let a0 = splitted[0].parse::().unwrap(); let a1 = splitted[1].parse::().unwrap(); let a2 = splitted[2].parse::().unwrap(); let a3 = splitted[3].parse::().unwrap(); (a0, a1, a2, a3) } fn read_vec_any(&mut self) -> Vec where T: std::str::FromStr, T::Err: std::fmt::Debug, { let buf = self.read_line(); buf.trim().split(' ').map(|s| s.parse::().unwrap()).collect::>() } fn read_vec_i64(&mut self) -> Vec { self.read_vec_any::() } fn read_vec_usize(&mut self) -> Vec { self.read_vec_any::() } fn read_vec_str(&mut self) -> Vec { self.read_vec_any::() } fn read_i64_1(&mut self) -> i64 { self.read_any_1::() } fn read_i64_2(&mut self) -> (i64, i64) { self.read_any_2::() } fn read_i64_3(&mut self) -> (i64, i64, i64) { self.read_any_3::() } fn read_i64_4(&mut self) -> (i64, i64, i64, i64) { self.read_any_4::() } fn read_usize_1(&mut self) -> usize { self.read_any_1::() } fn read_usize_2(&mut self) -> (usize, usize) { self.read_any_2::() } fn read_usize_3(&mut self) -> (usize, usize, usize) { self.read_any_3::() } fn read_usize_4(&mut self) -> (usize, usize, usize, usize) { self.read_any_4::() } } pub struct ProconReader { buf_read: R, } impl ProconReader { pub fn new(buf_read: R) -> ProconReader { ProconReader { buf_read } } } impl IProconReader for ProconReader { fn read_line(&mut self) -> String { let mut buffer = String::new(); self.buf_read.read_line(&mut buffer).unwrap(); buffer.trim().to_string() } } } use union_find::*; pub mod union_find { #[derive(Clone, Copy, Debug, PartialEq, Eq)] struct Root { count: i32, } #[derive(Clone, Copy, Debug, PartialEq, Eq)] enum Node { Root { root: Root }, NonRoot { parent_index: usize }, } #[derive(Clone, Copy, Debug, PartialEq, Eq)] struct RootAndIndex { root: Root, index: usize, } #[derive(Clone, Debug)] pub struct UnionFind { nodes: Vec, } impl UnionFind { pub fn new(n: usize) -> UnionFind { UnionFind { nodes: vec![Node::Root { root: Root { count: 1 } }; n] } } fn root_node(&mut self, index: usize) -> RootAndIndex { match self.nodes[index] { Node::Root { root } => RootAndIndex { root, index }, Node::NonRoot { parent_index } => { let root_and_index = self.root_node(parent_index); self.nodes[index] = Node::NonRoot { parent_index: root_and_index.index }; root_and_index } } } pub fn root(&mut self, index: usize) -> usize { self.root_node(index).index } pub fn same_count(&mut self, index: usize) -> i32 { self.root_node(index).root.count } pub fn same(&mut self, x: usize, y: usize) -> bool { self.root(x) == self.root(y) } pub fn num_groups(&self) -> usize { self.nodes.iter().filter(|&node| matches!(node, Node::Root { .. })).count() } pub fn unite(&mut self, x: usize, y: usize) { if self.same(x, y) { return; } let x_root_node = self.root_node(x); let y_root_node = self.root_node(y); let x_count = x_root_node.root.count; let y_count = y_root_node.root.count; let x_root_index = x_root_node.index; let y_root_index = y_root_node.index; if x_count < y_count { self.nodes[x_root_index] = Node::NonRoot { parent_index: y_root_index }; self.nodes[y_root_index] = Node::Root { root: Root { count: x_count + y_count } } } else { self.nodes[y_root_index] = Node::NonRoot { parent_index: x_root_index }; self.nodes[x_root_index] = Node::Root { root: Root { count: x_count + y_count } } } } } }