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use crate::internal::*;
use crate::post_tree::post_tree;
pub fn postorder(nn: usize, parent: &[isize], nv: &[isize], f_size: &[isize]) -> Vec<isize> {
// output
let mut order: Vec<isize> = vec![0; nn];
// local workspace
let mut child: Vec<isize> = vec![0; nn];
let mut sibling: Vec<isize> = vec![0; nn];
for j in 0..nn {
child[j] = EMPTY;
sibling[j] = EMPTY;
}
// Place the children in link lists - bigger elements tend to be last.
let mut j: isize = nn as isize - 1;
while j >= 0 {
if nv[j as usize] > 0 {
// This is an element.
let p = parent[j as usize];
if p != EMPTY {
// Place the element in link list of the children its parent
// bigger elements will tend to be at the end of the list.
sibling[j as usize] = child[p as usize];
child[p as usize] = j;
}
}
j -= 1;
}
#[cfg(feature = "debug1")]
{
// var nels, ff int
debug1_print!("\n\n================================ AMD_postorder:\n");
let mut nels = 0;
for j in 0..nn {
if nv[j] > 0 {
debug1_print!(
"{} : nels {} npiv {} size {} parent {} maxfr {}\n",
j,
nels,
nv[j],
f_size[j],
parent[j],
f_size[j]
);
// This is an element. Dump the link list of children.
let mut nchild = 0;
debug1_print!(" Children:");
let mut ff = child[j];
while ff != EMPTY {
debug1_print!(" {}", ff);
debug_assert!(parent[ff as usize] == j as isize);
nchild += 1;
debug_assert!(nchild < nn);
ff = sibling[ff as usize];
}
debug1_println!();
let p = parent[j];
if p != EMPTY {
debug_assert!(nv[p as usize] > 0);
}
nels += 1;
}
}
debug1_println!(
"\n\nGo through the children of each node, and put
the biggest child last in each list:"
);
}
// Place the largest child last in the list of children for each node.
for i in 0..nn {
if nv[i] > 0 && child[i] != EMPTY {
let mut nchild = 0;
{
debug1_print!("Before partial sort, element {}\n", i);
let mut f = child[i];
while f != EMPTY {
debug_assert!(f >= 0 && f < nn as isize);
debug1_print!(" f: {} size: {}\n", f, f_size[f as usize]);
nchild += 1;
debug_assert!(nchild <= nn);
f = sibling[f as usize];
}
}
// Find the biggest element in the child list.
let mut fprev = EMPTY;
let mut maxfrsize = EMPTY;
let mut bigfprev = EMPTY;
let mut bigf = EMPTY;
let mut f = child[i];
while f != EMPTY {
debug_assert!(f >= 0 && f < nn as isize);
let frsize = f_size[f as usize];
if frsize >= maxfrsize {
// This is the biggest seen so far.
maxfrsize = frsize;
bigfprev = fprev;
bigf = f;
}
fprev = f;
f = sibling[f as usize];
}
debug_assert!(bigf != EMPTY);
let fnext = sibling[bigf as usize];
debug1_print!(
"bigf {} maxfrsize {} bigfprev {} fnext {} fprev {}\n",
bigf,
maxfrsize,
bigfprev,
fnext,
fprev
);
if fnext != EMPTY {
// If fnext is EMPTY then bigf is already at the end of list.
if bigfprev == EMPTY {
// Delete bigf from the element of the list.
child[i] = fnext;
} else {
// Delete bigf from the middle of the list.
sibling[bigfprev as usize] = fnext;
}
// Put bigf at the end of the list.
sibling[bigf as usize] = EMPTY;
debug_assert!(child[i] != EMPTY);
debug_assert!(fprev != bigf);
debug_assert!(fprev != EMPTY);
sibling[fprev as usize] = bigf;
}
{
debug1_print!("After partial sort, element {}\n", i);
let mut f = child[i];
while f != EMPTY {
debug_assert!(f >= 0 && f < nn as isize);
debug1_print!(" {} {}\n", f, f_size[f as usize]);
debug_assert!(nv[f as usize] > 0);
nchild -= 1;
f = sibling[f as usize];
}
debug_assert!(nchild == 0);
}
}
}
// Postorder the assembly tree.
for i in 0..nn {
order[i] = EMPTY;
}
let mut k = 0;
let mut stack: Vec<isize> = vec![0; nn];
for i in 0..nn {
if parent[i] == EMPTY && nv[i] > 0 {
debug1_print!("Root of assembly tree {}\n", i);
k = post_tree(i, k, &mut child, &sibling, &mut order, &mut stack, nn);
}
}
order
}