master > master: code-rust - debugging im Alg

code/rust/src/graphs/tarjan.rs

@@ -7,6 +7,7 @@ use std::hash::Hash;
 use std::collections::HashMap;
 
 use crate::core::utils;
+use crate::core::log::log_debug;
 use crate::stacks::stack::Stack;
 use crate::graphs::graph::Graph;
 
@@ -28,10 +29,10 @@ enum State {
 
 /// # Tarjan Algorithm #
 /// Runs the Tarjan-Algorithm to compute the strongly connected components.
-pub fn tarjan_algorithm<T>(gph: &Graph<T>) -> Vec<Vec<T>>
-    where T: Eq + Hash + Clone + Display
+pub fn tarjan_algorithm<T>(gph: &Graph<T>, debug: bool) -> Vec<Vec<T>>
+    where T: Eq + Hash + Clone + Copy + Display
 {
-    let mut ctx = Context::new(&gph);
+    let mut ctx = Context::new(&gph, debug);
 
     for u in gph.nodes.iter() {
         tarjan_visit(gph, u, &mut ctx);
@@ -41,7 +42,7 @@ pub fn tarjan_algorithm<T>(gph: &Graph<T>) -> Vec<Vec<T>>
 
 /// recursive depth-first search algorithm to compute components
 fn tarjan_visit<T>(gph: &Graph<T>, v: &T, ctx: &mut Context<T>)
-    where T: Eq + Hash + Clone + Display
+    where T: Eq + Hash + Clone + Copy + Display
 {
     if !(ctx.get_state(v) == State::UNTOUCHED) {
         return;
@@ -66,6 +67,10 @@ fn tarjan_visit<T>(gph: &Graph<T>, v: &T, ctx: &mut Context<T>)
         }
     }
     ctx.set_state(v, State::FINISHED);
+    if ctx.debug {
+        let info = ctx.get_info(&v);
+        log_debug!("node, index, component: ({}, {}, {})", info.node, info.index, info.root);
+    }
 
     if ctx.get_index(v) == ctx.get_root(v) {
         let mut component: Vec<T> = Vec::new();
@@ -73,9 +78,7 @@ fn tarjan_visit<T>(gph: &Graph<T>, v: &T, ctx: &mut Context<T>)
             let u = ctx.top();
             ctx.pop();
             component.push(u.clone());
-            if u == *v {
-                break;
-            }
+            if u == *v { break; }
         }
         ctx.components.push(component);
     }
@@ -86,7 +89,8 @@ fn tarjan_visit<T>(gph: &Graph<T>, v: &T, ctx: &mut Context<T>)
 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 #[derive(Clone, Copy)]
-struct NodeInformation {
+struct NodeInformation<T> {
+    node: T,
     root: usize,
     index: usize,
     state: State,
@@ -95,23 +99,25 @@ struct NodeInformation {
 struct Context<T> {
     stack: Stack<T>,
     max_index: usize,
-    infos: HashMap<T, NodeInformation>,
+    infos: HashMap<T, NodeInformation<T>>,
     components: Vec<Vec<T>>,
+    debug: bool,
 }
 
 impl<T> Context<T>
-    where T: Eq + Hash + Clone + Display
+    where T: Eq + Hash + Clone + Copy + Display
 {
-    fn new(gph: &Graph<T>) -> Context<T> {
-        let mut infos = HashMap::<T, NodeInformation>::new();
+    fn new(gph: &Graph<T>, debug: bool) -> Context<T> {
+        let mut infos = HashMap::<T, NodeInformation<T>>::new();
         for u in gph.nodes.iter() {
-            infos.entry(u.clone()).or_insert(NodeInformation::new());
+            infos.entry(u.clone()).or_insert(NodeInformation::<T>::new(&u));
         }
         return Context {
             stack: Stack::new(),
             max_index: 0,
             infos: infos,
             components: vec![],
+            debug: debug,
         };
     }
 
@@ -127,7 +133,7 @@ impl<T> Context<T>
         return self.stack.pop();
     }
 
-    fn update_infos(self: &mut Self, u: &T, info: NodeInformation) {
+    fn update_infos(self: &mut Self, u: &T, info: NodeInformation<T>) {
         self.infos.insert(u.clone(), info);
     }
 
@@ -149,25 +155,29 @@ impl<T> Context<T>
         self.update_infos(u, info);
     }
 
+    fn get_info(self: &mut Self, u: &T) -> NodeInformation<T> {
+        return *self.infos.get(u).unwrap();
+    }
+
     fn get_state(self: &mut Self, u: &T) -> State {
-        let info = *self.infos.get(u).unwrap();
-        return info.state;
+        return self.get_info(u).state;
     }
 
     fn get_root(self: &mut Self, u: &T) -> usize {
-        let info = *self.infos.get(u).unwrap();
-        return info.root;
+        return self.get_info(u).root;
     }
 
     fn get_index(self: &mut Self, u: &T) -> usize {
-        let info = *self.infos.get(u).unwrap();
-        return info.index;
+        return self.get_info(u).index;
     }
 }
 
-impl NodeInformation {
-    fn new() -> NodeInformation {
+impl<T> NodeInformation<T>
+    where T: Clone + Copy
+{
+    fn new(node: &T) -> NodeInformation<T> {
         return NodeInformation {
+            node: node.clone(),
             root: 0,
             index: 0,
             state: State::UNTOUCHED,

code/rust/tests/test_graphs/test_tarjan.rs

@@ -63,9 +63,9 @@ fn fixture_graph3() -> graph::Graph<i32> {
 #[case(fixture_graph2(), vec![vec![1], vec![6], vec![7], vec![2,3,4,5]])]
 #[case(fixture_graph3(), vec![vec![1,2,3,4,5], vec![7], vec![6,8]])]
 fn test_tarjan<T>(#[case] gph: graph::Graph<T>, #[case] expected: Vec<Vec<T>>)
-    where T: Eq + Hash + Clone + Display
+    where T: Eq + Hash + Clone + Copy + Display
 {
-    let components = tarjan::tarjan_algorithm(&gph);
+    let components = tarjan::tarjan_algorithm(&gph, false);
     assert_components_eq(&components, &expected)
 }