Add timing of complete program

vertex_cover/src/main.rs

@@ -163,6 +163,7 @@ struct Args {
 }
 
 fn main() {
+    let total_start = std::time::Instant::now();
     let args = Args::parse();
 
     let graph = parse(args.filename);
@@ -207,4 +208,5 @@ fn main() {
             println!("{}", n + 1);
         }
     }
+    eprintln!("Total time: {:?}", total_start.elapsed());
 }