Create: 0684-redundant-connection.rs

rust/0684-redundant-connection.rs

@@ -0,0 +1,60 @@
+use std::cmp::Ordering;
+
+struct UnionFind {
+    parent: Vec<usize>,
+    rank: Vec<i32>,
+}
+
+impl UnionFind {
+    fn new(n: usize) -> Self {
+        UnionFind {
+            parent: (0..(n + 1)).collect(),
+            rank: vec![1; n + 1],
+        }
+    }
+
+    fn find(&mut self, n: usize) -> usize {
+        let mut p = self.parent[n];
+
+        while p != self.parent[p] {
+            self.parent[p] = self.parent[self.parent[p]];
+            p = self.parent[p];
+        }
+
+        p
+    }
+
+    fn union(&mut self, n1: usize, n2: usize) -> bool {
+        let p1 = self.find(n1);
+        let p2 = self.find(n2);
+
+        if p1 == p2 {
+            return false;
+        }
+        match self.rank[p1].cmp(&self.rank[p2]) {
+            Ordering::Greater => {
+                self.parent[p2] = p1;
+                self.rank[p1] += self.rank[p2];
+            }
+            _ => {
+                self.parent[p1] = p2;
+                self.rank[p2] = self.rank[p1];
+            }
+        }
+        true
+    }
+}
+
+impl Solution {
+    pub fn find_redundant_connection(edges: Vec<Vec<i32>>) -> Vec<i32> {
+        let mut union_find = UnionFind::new(edges.len() + 1);
+
+        for edge in edges {
+            let (n1, n2) = (edge[0] as usize, edge[1] as usize);
+            if !union_find.union(n1, n2) {
+                return vec![n1 as i32, n2 as i32];
+            }
+        }
+        unreachable!()
+    }
+}