New

Exercise/P2097 资料分发 1.rs

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