refactor dijkstra

src/euler81/src/main.rs

@@ -110,7 +110,7 @@ impl Matrix {
 
 fn main() {
     let mut matrix = Matrix::load(Path::new(FILENAME));
-    let mut dijkstra = Dijkstra::new(Box::new(&mut matrix));
+    let mut dijkstra = Dijkstra::new(&mut matrix);
     dijkstra.solve();
     let result = matrix
         .get((LENGTH - 1, LENGTH - 1))