added my name as instructed

README.md

@@ -34,3 +34,5 @@ cargo codspeed run -m walltime
 ```
 
 Note: You can also set the `CODSPEED_RUNNER_MODE` environment variable to `walltime` to avoid passing `-m walltime` every time.
+
+Name: Mehdi

src/bfs.rs

@@ -1,4 +1,7 @@
-use std::collections::HashSet;
+use std::collections::{
+    HashSet,
+    VecDeque
+};
 
 /// A simple graph represented as an adjacency list
 #[derive(Debug, Clone)]
@@ -17,31 +20,36 @@ impl Graph {
     pub fn add_edge(&mut self, from: usize, to: usize) {
         self.adjacency[from].push(to);
     }
-
     pub fn num_nodes(&self) -> usize {
         self.adjacency.len()
     }
 }
 
-/// Naive BFS implementation using Vec as a queue (intentionally slow)
+/// Naive BFS implementation using VecDeque
 /// Returns the order in which nodes were visited
 pub fn bfs_naive(graph: &Graph, start: usize) -> Vec<usize> {
-    let mut visited = HashSet::new();
-    let mut queue = Vec::new(); // Using Vec instead of VecDeque - intentionally inefficient!
-    let mut result = Vec::new();
+    let n_nodes = graph.num_nodes();
+
+    let mut visited = HashSet::with_capacity(n_nodes);
+    let mut queue = VecDeque::with_capacity(n_nodes);
+    let mut result = Vec::with_capacity(n_nodes);
 
-    queue.push(start);
+    queue.push_back(start);
     visited.insert(start);
 
     while !queue.is_empty() {
-        // remove(0) is O(n) - this makes BFS slow!
-        let node = queue.remove(0);
+        let node = queue
+            .pop_front()
+            .expect(
+                "This used to be a remove(0), so I assume underlying value exists"
+            )
+        ;
         result.push(node);
 
         if let Some(neighbors) = graph.adjacency.get(node) {
             for &neighbor in neighbors {
                 if visited.insert(neighbor) {
-                    queue.push(neighbor);
+                    queue.push_back(neighbor);
                 }
             }
         }