140 lines
3.2 KiB
Rust
140 lines
3.2 KiB
Rust
use std::io;
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pub mod graph {
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// 定义容器结构体：节点数量 + 邻接表
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pub struct Container {
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pub num: usize,
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pub adj: Vec<Vec<usize>>,
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pub parent: Vec<usize>, // 并查集父节点
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}
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impl Container {
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// 初始化图和并查集
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pub fn new(n: usize) -> Self {
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let mut parent = vec![0; n];
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for i in 0..n {
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parent[i] = i;
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}
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Self {
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num: n,
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adj: vec![vec![]; n],
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parent,
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}
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}
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// 查找根节点（带路径压缩）
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pub fn find(&mut self, i: usize) -> usize {
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if self.parent[i] != i {
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let root = self.find(self.parent[i]);
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self.parent[i] = root;
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}
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self.parent[i]
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}
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// 合并两个集合
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pub fn merge(&mut self, i: usize, j: usize) {
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let fi = self.find(i);
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let fj = self.find(j);
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if fi != fj {
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self.parent[fi] = fj;
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}
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}
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// 添加一条边
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pub fn add_edge(&mut self, a: usize, b: usize) {
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self.adj[a].push(b);
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self.adj[b].push(a); // 如果是无向图
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self.merge(a, b); // 顺便在并查集中合并
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}
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// 打印邻接表
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pub fn show(&self) {
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for (i, edges) in self.adj.iter().enumerate() {
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println!("{} -> {:?}", i, edges);
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}
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}
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// 判断两个节点是否连通
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pub fn connected(&mut self, a: usize, b: usize) -> bool {
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self.find(a) == self.find(b)
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}
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}
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}
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fn main() {
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use graph::Container;
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// 示例：5个节点
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let mut g = Container::new(5);
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g.add_edge(0, 1);
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g.add_edge(1, 2);
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g.add_edge(3, 4);
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g.show();
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println!("0-2 connected? {}", g.connected(0, 2));
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println!("0-4 connected? {}", g.connected(0, 4));
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}
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use std::io::{self, Read};
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fn find(parent: &mut Vec<usize>, x: usize) -> usize {
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if parent[x] != x {
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parent[x] = find(parent, parent[x]);
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}
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parent[x]
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}
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fn merge(parent: &mut Vec<usize>, a: usize, b: usize) {
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let fa = find(parent, a);
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let fb = find(parent, b);
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if fa != fb {
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parent[fb] = fa;
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}
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}
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fn main() {
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let mut input = String::new();
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io::stdin().read_to_string(&mut input).unwrap();
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let mut iter = input.split_whitespace();
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let n: usize = iter.next().unwrap().parse().unwrap();
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let m: usize = iter.next().unwrap().parse().unwrap();
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let mut parent = (0..=n).collect::<Vec<_>>();
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for _ in 0..m {
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let a: usize = iter.next().unwrap().parse().unwrap();
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let b: usize = iter.next().unwrap().parse().unwrap();
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merge(&mut parent, a, b);
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}
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let mut roots = std::collections::HashSet::new();
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for i in 1..=n {
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roots.insert(find(&mut parent, i));
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}
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println!("{}", roots.len());
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}
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/*
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并查集
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vector<int> parent(n);
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for(int i = 0; i < n; i++){
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parent[i] = i;
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}
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int find(int i){
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if(parent[i] != i){
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parent[i] = find(parent[i]);
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}
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return parent[i];
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}
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void merge(int i, int j){
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int fi = find(i);
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int fj = find(j);
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if(fi != fj) parent[j] = fi;
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}
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*/ |