Add todos

src/algorithms.rs

@@ -61,6 +61,7 @@ pub struct DijkstraResult<V: Copy> {
 }
 
 // TODO: Generalize the return type of the weight function.
+// TODO: Add complexity information for Dijkstra's algorithm variants.
 /// [Dijkstra's algorithm] with custom edge weights, returns minimum distances and predecessors.
 ///
 /// Calculates the shortest paths from `source` to all vertices in `graph` with edge weights given
@@ -459,6 +460,7 @@ where
     }
 }
 
+// TODO: 'visited' is already encoded in 'predecessors', except for 'source', which is visited, but has no predecessor.
 /// Return data type for [`dfs`].
 pub struct DfsResult<V: Copy> {
     /// Vertex map indicating which vertices were visited during the search.