Added reminder to update bellman-ford to return Err() when the graph contains negative circles

LMH01 · LMH01 · commit be39f481e2dc · 2023-06-18T23:58:44.000+02:00
diff --git a/src/algorithms.rs b/src/algorithms.rs
@@ -176,18 +176,20 @@ pub fn bellman_ford<T: Display + Eq + Clone + Hash>(graph: &mut Graph<T>, source
             }
 
             for edge in &node_ref.edges {
-                let target_node = edge.target.clone();
+                let target_node = Rc::clone(&edge.target);
+                let mut target_node_ref = target_node.borrow_mut();
                 let new_distance = node_ref.distance + edge.weight;
 
-                if new_distance < target_node.borrow().distance {
-                    target_node.borrow_mut().distance = new_distance;
+                if new_distance < target_node_ref.distance {
+                    target_node_ref.distance = new_distance;
                     let mut shortest_path = node_ref.shortest_path.clone();
-                    shortest_path.push(node.clone());
-                    target_node.borrow_mut().shortest_path = shortest_path;
+                    shortest_path.push(Rc::clone(&node));
+                    target_node_ref.shortest_path = shortest_path;
                 }
             }
         }
     }
+    //TODO Add in check that detects negative circles and return Err() when found, update docs accordingly and add in a test that checks that
 
     Ok(ShortestPathTree::from_graph(&graph, &source_node_id))
 }
diff --git a/src/lib.rs b/src/lib.rs
@@ -43,7 +43,8 @@
 //! ```
 
 use std::{fmt::{Display, Debug}, rc::Rc, cell::RefCell, collections::HashMap, hash::Hash};
-
+// TODO update graph print to properly print negative edge weights
+// TODO add available from_instruction feature to main doc page and explain briefly what it does
 /// Contains implementations for the graph to work.
 mod graph;
 /// Contains all algorithms that are implemented in this crate.

Original file line number	Diff line number	Diff line change
`@@ -176,18 +176,20 @@ pub fn bellman_ford<T: Display + Eq + Clone + Hash>(graph: &mut Graph<T>, source`
`176`	`176`	`}`
`177`	`177`
`178`	`178`	`for edge in &node_ref.edges {`
`179`		`- let target_node = edge.target.clone();`
	`179`	`+ let target_node = Rc::clone(&edge.target);`
	`180`	`+ let mut target_node_ref = target_node.borrow_mut();`
`180`	`181`	`let new_distance = node_ref.distance + edge.weight;`
`181`	`182`
`182`		`- if new_distance < target_node.borrow().distance {`
`183`		`- target_node.borrow_mut().distance = new_distance;`
	`183`	`+ if new_distance < target_node_ref.distance {`
	`184`	`+ target_node_ref.distance = new_distance;`
`184`	`185`	`let mut shortest_path = node_ref.shortest_path.clone();`
`185`		`- shortest_path.push(node.clone());`
`186`		`- target_node.borrow_mut().shortest_path = shortest_path;`
	`186`	`+ shortest_path.push(Rc::clone(&node));`
	`187`	`+ target_node_ref.shortest_path = shortest_path;`
`187`	`188`	`}`
`188`	`189`	`}`
`189`	`190`	`}`
`190`	`191`	`}`
	`192`	`+ //TODO Add in check that detects negative circles and return Err() when found, update docs accordingly and add in a test that checks that`
`191`	`193`
`192`	`194`	`Ok(ShortestPathTree::from_graph(&graph, &source_node_id))`
`193`	`195`	`}`