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pub struct GenTree<T> {
nodes: Vec<T>,
height: usize,
}
#[inline(always)]
pub fn compute_num_nodes(height:usize)->usize{
return (1 << height) - 1;
}
impl<T> GenTree<T> {
#[inline(always)]
pub fn get_height(&self) -> usize {
self.height
}
pub fn from_dfs<F:FnMut()->T>(mut func:F,height:usize)->GenTree<T>{
assert!(height>=1);
let mut tree=GenTree::from_bfs(&mut ||{unsafe{std::mem::uninitialized()}},height);
{
let t=tree.create_down_mut();
t.dfs_preorder(|node:&mut T|{
*node=func();
});
}
tree
}
pub fn from_dfs_backwards<F:FnMut()->T>(mut func:F,height:usize)->GenTree<T>{
assert!(height>=1);
let mut tree=GenTree::from_bfs(&mut ||{unsafe{std::mem::uninitialized()}},height);
{
let t=tree.create_down_mut();
t.dfs_postorder(|node:&mut T|{
*node=func();
});
}
tree
}
pub fn from_bfs<F:FnMut()->T>(mut func:F,height:usize)->GenTree<T>{
assert!(height>=1);
let num_nodes=self::compute_num_nodes(height);
let mut vec=Vec::with_capacity(num_nodes);
for _ in 0..num_nodes{
vec.push(func())
}
GenTree{
nodes:vec,
height:height,
}
}
pub fn bfs<F:FnMut(&T)>(&self,mut func:F){
for i in self.nodes.iter(){
func(i);
}
}
pub fn bfs_mut<F:FnMut(&mut T)>(&mut self,mut func:F){
for i in self.nodes.iter_mut(){
func(i);
}
}
#[inline(always)]
pub fn get_level_desc(&self)->LevelDesc{
LevelDesc{depth:0}
}
#[inline(always)]
pub fn create_down(&self)->DownT<T>{
let k=DownT{remaining:self,nodeid:NodeIndex(0),first_leaf:NodeIndex::first_leaf(self.nodes.len())};
k
}
#[inline(always)]
pub fn create_down_mut(&mut self)->DownTMut<T>{
let k=DownTMut{remaining:self,nodeid:NodeIndex(0),first_leaf:NodeIndex::first_leaf(self.nodes.len()),phantom:PhantomData};
k
}
#[inline(always)]
pub fn into_dfs_preorder<F:FnMut(T)>(self,func:F){
cons::downt_into_dfs_preorder(self,func);
}
#[inline(always)]
pub fn get_nodes(&self)->&[T]{
&self.nodes
}
}
#[derive(Copy,Clone,Debug)]
struct NodeIndex(usize);
impl NodeIndex{
#[inline(always)]
fn get_children(self) -> (NodeIndex, NodeIndex) {
let NodeIndex(a) = self;
(NodeIndex(2 * a + 1), NodeIndex(2 * a + 2))
}
fn first_leaf(nodes:usize)->NodeIndex{
NodeIndex(nodes/2)
}
}
pub trait CTreeIterator:Sized{
type Item;
fn next(self)->(Self::Item,Option<(Self,Self)>);
fn zip<F:CTreeIterator>(self,f:F)->ZippedDownTMut<Self,F>{
ZippedDownTMut::new(self,f)
}
fn dfs_preorder<F:FnMut(Self::Item)>(self,mut func:F){
fn rec<C:CTreeIterator,F:FnMut(C::Item)>(a:C,func:&mut F){
let (nn,rest)=a.next();
func(nn);
match rest{
Some((left,right))=>{
rec(left,func);
rec(right,func);
},
None=>{
}
}
}
rec(self,&mut func);
}
fn dfs_postorder<F:FnMut(Self::Item)>(self,mut func:F){
fn rec<C:CTreeIterator,F:FnMut(C::Item)>(a:C,func:&mut F){
let (nn,rest)=a.next();
match rest{
Some((left,right))=>{
rec(right,func);
rec(left,func);
},
None=>{
}
}
func(nn);
}
rec(self,&mut func);
}
}
use std::marker::PhantomData;
unsafe impl<'a,T:'a> std::marker::Send for DownTMut<'a,T>{}
pub struct DownTMut<'a,T:'a>{
remaining:*mut GenTree<T>,
nodeid:NodeIndex,
first_leaf:NodeIndex,
phantom:PhantomData<&'a T>
}
impl<'a,T:'a> CTreeIterator for DownTMut<'a,T>{
type Item=&'a mut T;
fn next(self)->(Self::Item,Option<(Self,Self)>){
let a=unsafe{&mut (*self.remaining).nodes[self.nodeid.0]};
if self.nodeid.0>=self.first_leaf.0{
(a,None)
}else{
let (l,r)=self.nodeid.get_children();
let j=(
DownTMut{remaining:self.remaining,nodeid:l,first_leaf:self.first_leaf,phantom:PhantomData},
DownTMut{remaining:self.remaining,nodeid:r,first_leaf:self.first_leaf,phantom:PhantomData}
);
(a,Some(j))
}
}
}
pub struct DownT<'a,T:'a>{
remaining:&'a GenTree<T>,
nodeid:NodeIndex,
first_leaf:NodeIndex,
}
impl<'a,T:'a> CTreeIterator for DownT<'a,T>{
type Item=&'a T;
fn next(self)->(Self::Item,Option<(Self,Self)>){
let a=&self.remaining.nodes[self.nodeid.0];
if self.nodeid.0>=self.first_leaf.0{
(a,None)
}else{
let (l,r)=self.nodeid.get_children();
let j=(
DownT{remaining:self.remaining,nodeid:l,first_leaf:self.first_leaf},
DownT{remaining:self.remaining,nodeid:r,first_leaf:self.first_leaf}
);
(a,Some(j))
}
}
}
pub struct ZippedDownTMut<T1:CTreeIterator,T2:CTreeIterator>{
a:T1,
b:T2,
}
impl<T1:CTreeIterator,T2:CTreeIterator> ZippedDownTMut<T1,T2>{
#[inline(always)]
fn new(a:T1,b:T2)->ZippedDownTMut<T1,T2>{
ZippedDownTMut{a:a,b:b}
}
}
impl<T1:CTreeIterator,T2:CTreeIterator> CTreeIterator for ZippedDownTMut<T1,T2>{
type Item=(T1::Item,T2::Item);
fn next(self)->(Self::Item,Option<(Self,Self)>){
let (a_item,a_rest)=self.a.next();
let (b_item,b_rest)=self.b.next();
let item=(a_item,b_item);
match (a_rest,b_rest){
(Some(a_rest),Some(b_rest))=>{
let f1=ZippedDownTMut{a:a_rest.0,b:b_rest.0};
let f2=ZippedDownTMut{a:a_rest.1,b:b_rest.1};
(item,Some((f1,f2)))
},
_ =>{
(item,None)
}
}
}
}
pub use wrap::Wrap;
mod wrap{
use super::*;
pub struct Wrap<'a,T:'a>{
a:LevelIter<DownTMut<'a,T>>
}
impl<'a,T:'a> Wrap<'a,T>{
#[inline(always)]
pub fn new(a:&'a mut LevelIter<DownTMut<T>>)->Wrap<'a,T>{
let inner=&a.a;
let k=DownTMut{remaining:inner.remaining,nodeid:inner.nodeid,first_leaf:inner.first_leaf,phantom:inner.phantom};
let j=LevelIter{a:k,leveld:a.leveld};
Wrap{a:j}
}
}
impl<'a,T:'a> CTreeIterator for Wrap<'a,T>{
type Item=(LevelDesc,&'a mut T);
fn next(self)->(Self::Item,Option<(Self,Self)>){
let Wrap{a}=self;
let (item,mm)=a.next();
match mm{
Some((left,right))=>{
let left=Wrap{a:left};
let right=Wrap{a:right};
return (item,Some((left,right)));
},
None=>{
return (item,None);
}
}
}
}
}
mod cons{
use super::*;
struct DownTConsume<'a,T:'a>{
remaining:*mut GenTree<T>,
nodeid:NodeIndex,
first_leaf:NodeIndex,
phantom:PhantomData<&'a T>
}
pub fn downt_into_dfs_preorder<T,F:FnMut(T)>(mut tree:GenTree<T>,func:F){
{
let t=DownTConsume{remaining:&mut tree,nodeid:NodeIndex(0),first_leaf:NodeIndex::first_leaf(tree.nodes.len()),phantom:PhantomData};
t.dfs_preorder(func);
}
for a in tree.nodes.drain(..){
std::mem::forget(a);
}
}
impl<'a,T:'a> CTreeIterator for DownTConsume<'a,T>{
type Item=T;
fn next(self)->(Self::Item,Option<(Self,Self)>){
let mut val=unsafe{std::mem::uninitialized()};
let a=unsafe{&mut (*self.remaining).nodes[self.nodeid.0]};
unsafe{std::ptr::copy(&mut val,a,1)};
if self.nodeid.0>=self.first_leaf.0{
(val,None)
}else{
let (l,r)=self.nodeid.get_children();
let j=(
DownTConsume{remaining:self.remaining,nodeid:l,first_leaf:self.first_leaf,phantom:PhantomData},
DownTConsume{remaining:self.remaining,nodeid:r,first_leaf:self.first_leaf,phantom:PhantomData}
);
(val,Some(j))
}
}
}
}
#[derive(Copy,Clone)]
pub struct LevelDesc{
depth:usize
}
impl LevelDesc{
#[inline(always)]
fn next_down(&self)->LevelDesc{
LevelDesc{depth:self.depth+1}
}
#[inline(always)]
pub fn get_depth(&self)->usize{
self.depth
}
}
pub struct LevelIter<T:CTreeIterator>{
a:T,
leveld:LevelDesc
}
impl <T:CTreeIterator> LevelIter<T>{
#[inline(always)]
pub fn new(a:T,leveld:LevelDesc)->LevelIter<T>{
return LevelIter{a,leveld};
}
}
impl<T:CTreeIterator> CTreeIterator for LevelIter<T>{
type Item=(LevelDesc,T::Item);
fn next(self)->(Self::Item,Option<(Self,Self)>){
let LevelIter{a,leveld}=self;
let (nn,rest)=a.next();
let r=(leveld,nn);
match rest{
Some((left,right))=>{
let ln=leveld.next_down();
let ll=LevelIter{a:left,leveld:ln};
let rr=LevelIter{a:right,leveld:ln};
(r,Some((ll,rr)))
},
None=>{
(r,None)
}
}
}
}
#[cfg(test)]
mod tests {
#[test]
fn it_works() {
}
}