algos/src/ssc.rs

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]);
    }

    0
}