Start working on course 2 assignment 1

src/main.rs

@@ -50,8 +50,9 @@ fn c1a4() {
 
 #[allow(dead_code)]
 fn c2a1() {
-    let g = read_to_directed_graph("data/course_2_assignment_1.txt").unwrap();
-    let s = ssc(g);
+    // let g = read_to_directed_graph("data/course_2_assignment_1.txt").unwrap();
+    let g = read_to_directed_graph("data/course_2_assignment_1_test.txt").unwrap();
+    let s = ssc(g.0, g.1);
     println!("{:?}", s);
 }
 

src/ssc.rs

@@ -1,5 +1,47 @@
-use crate::util::Graph;
+use crate::util::DirectedGraph;
+
+fn dfs(mut g: &mut DirectedGraph, node: usize, mut time: &mut usize) -> () {
+    g.explored[node] = true;
+    for i in 0..g.nodes[node].len() {
+        let j = g.nodes[node][i];
+        if !g.explored[j] {
+            dfs(&mut g, j, &mut time);
+        }
+    }
+    *time += 1;
+    g.time[node] = *time;
+}
+
+pub fn ssc(g: DirectedGraph, mut g_dash: DirectedGraph) -> u32 {
+    let mut time: usize = 0;
+    println!("ssc");
+
+    for i in (0..g_dash.nodes.len()).rev() {
+        if !g_dash.explored[i] {
+            dfs(&mut g_dash, i, &mut time);
+        }
+    }
+
+    println!("finished first dfs");
+
+    let mut time_to_index: Vec<usize> = vec![0; g.nodes.len()];
+
+    for i in 0..g_dash.nodes.len() {
+        time_to_index[g_dash.time[i] - 1] = i;
+    }
+
+    println!("finish time look-up");
+
+    for i in (0..time_to_index.len()).rev() {
+        let _node = time_to_index[i];
+        // println!("time: {:?} node: {:?}", i, node);
+    }
+
+    println!("finished second dfs");
+
+    for i in 0..g_dash.nodes.len() {
+        println!("f({})={}", i + 1, g_dash.time[i]);
+    }
 
-pub fn ssc(_g: Graph) -> u32 {
     0
 }

src/util.rs

@@ -9,6 +9,13 @@ pub struct Graph {
     pub edges: Vec<(u32, u32)>,
 }
 
+#[derive(Debug, Clone)]
+pub struct DirectedGraph {
+    pub nodes: Vec<Vec<usize>>,
+    pub explored: Vec<bool>,
+    pub time: Vec<usize>,
+}
+
 pub fn read_to_vector(path: &str) -> Result<Vec<i64>, io::Error> {
     let file = File::open(path)?;
     let br = BufReader::new(file);
@@ -52,22 +59,33 @@ pub fn read_to_graph(path: &str) -> Result<Graph, io::Error> {
     Ok(g)
 }
 
-pub fn read_to_directed_graph(path: &str) -> Result<Graph, io::Error> {
-    let mut g = Graph {
-        nodes: vec![],
-        edges: vec![],
+pub fn read_to_directed_graph(path: &str) -> Result<(DirectedGraph, DirectedGraph), io::Error> {
+    const NODES: usize = 9;
+    // const NODES: usize = 875714;
+    let mut g = DirectedGraph {
+        nodes: vec![vec![]; NODES],
+        explored: vec![false; NODES],
+        time: vec![0; NODES],
     };
+
+    let mut g_dash = DirectedGraph {
+        nodes: vec![vec![]; NODES],
+        explored: vec![false; NODES],
+        time: vec![0; NODES],
+    };
+
     let file = File::open(path)?;
     let br = BufReader::new(file);
 
     for line in br.lines() {
         let line = line?;
         let mut nodes = line.split_whitespace();
-        let first_node = nodes.next().unwrap().parse().unwrap();
-        let second_node = nodes.next().unwrap().parse().unwrap();
-        let edge = (first_node, second_node);
-        g.edges.push(edge);
+        let first_node: usize = nodes.next().unwrap().parse().unwrap();
+        let second_node: usize = nodes.next().unwrap().parse().unwrap();
+
+        g.nodes[first_node - 1].push(second_node - 1);
+        g_dash.nodes[second_node - 1].push(first_node - 1);
     }
-    println!("{:?}", g);
-    Ok(g)
+
+    Ok((g, g_dash))
 }