提出 #43651390

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ソースコード 拡げる

#![allow(non_snake_case)]


fn main(){
    let input=Input::input();
    let node=Node{
        track_id:!0,
        state:[0;N],
        hash:0,
        refs:0,
        score:(0..N).map(|i|input.score[0][i][0]).sum(),
    };
    let mut solver=BeamSearch::new(node);
    let ans=solver.solve(&input);

    for n in ans{
        if n==1{
            println!("A");
        } else {
            println!("B");
        }
    }
}


const N:usize=20;
use proconio::{*,marker::*};


struct Input{
    cmds:[[usize;3];TURN],
    score:[[[i16;TURN];N];TURN+1],
    zob:[u64;N],
}
impl Input{
    fn input()->Input{
        input!{
            turn:usize,
            i_cmds:[[Usize1;3];TURN],
        }
        assert_eq!(turn,TURN);
        let mut cmds=[[!0;3];TURN];
        for i in 0..TURN{
            for j in 0..3{
                cmds[i][j]=i_cmds[i][j];
            }
        }
        
        let mut score=[[[0;TURN];N];TURN+1];

        for i in (0..TURN).rev(){
            for &j in &cmds[i]{
                score[i][j][0]=score[i+1][j][1];
                for k in 1..TURN{
                    score[i][j][k]=score[i+1][j][k-1]+(k==1) as i16;
                }
            }

            for j in 0..N{
                if cmds[i].contains(&j){
                    continue;
                }
                for k in 0..TURN{
                    score[i][j][k]=score[i+1][j][k]+(k==0) as i16;
                }
            }
        }

        let mut zob=[0;N];
        use rand::prelude::*;
        let mut rng=rand_pcg::Pcg64Mcg::new(0);
        for i in 0..N{
            zob[i]=rng.gen();
        }

        Input{cmds,score,zob}
    }
}


#[allow(non_camel_case_types)]
type uint=u32;


#[derive(Clone,Default)]
struct Node{
    track_id:uint,
    score:i16,
    hash:u64,
    state:[i8;N],
    refs:u8,
}
impl Node{
    fn new_node(&self,input:&Input,turn:usize,cand:&Cand)->Node{
        let mut ret=self.clone();
        ret.apply(input,turn,cand);
        ret
    }
    
    fn apply(&mut self,input:&Input,turn:usize,cand:&Cand){
        for &n in &input.cmds[turn]{
            self.state[n]+=cand.op;
        }
        self.score=cand.eval_score;
        self.hash=cand.hash;
    }
}


#[derive(Clone)]
struct Cand{
    op:i8,
    parent:uint,
    eval_score:i16,
    hash:u64,
}
impl Cand {
    fn raw_score(&self,input:&Input)->i16{
        self.eval_score
    }
}


const MAX_WIDTH:usize=100000;
const TURN:usize=100;


struct BeamSearch{
    track:Vec<(uint,i8)>,
    nodes:Vec<Node>,
    free:Vec<usize>,
    at:usize,
    cands:Vec<Cand>,
}
impl BeamSearch{
    fn new(node:Node)->BeamSearch{
        const MAX_NODES:usize=MAX_WIDTH*TURN;
        // assert!(MAX_NODES<uint::MAX as usize);
        let mut nodes=vec![Node::default();MAX_WIDTH*2];
        nodes[0]=node;
        
        BeamSearch{
            free:(0..nodes.len()).collect(),
            nodes,
            at:1,
            track:Vec::with_capacity(MAX_NODES),
            cands:Vec::with_capacity(MAX_WIDTH),
        }
    }
    
    fn enum_cands(&self,input:&Input,turn:usize,cands:&mut Vec<Cand>){
        for &i in &self.free[..self.at]{
            self.append_cands(input,turn,i,cands);
        }
    }
    
    fn update<I:Iterator<Item=Cand>>(&mut self,input:&Input,turn:usize,cands:I){
        self.cands.clear();
        for cand in cands{
            self.nodes[cand.parent as usize].refs+=1;
            self.cands.push(cand);
        }

        for i in (0..self.at).rev(){
            if self.nodes[self.free[i]].refs==0{
                self.at-=1;
                self.free.swap(i,self.at);
            }
        }

        for cand in &self.cands{
            let node=&mut self.nodes[cand.parent as usize];
            node.refs-=1;
            let prev=node.track_id;

            let new=if node.refs==0{
                node.apply(input,turn,cand);
                node
            }
            else{
                let mut new=node.new_node(input,turn,cand);
                new.refs=0;
                let idx=self.free[self.at];
                self.at+=1;
                self.nodes[idx]=new;
                &mut self.nodes[idx]
            };

            self.track.push((prev,cand.op));
            new.track_id=self.track.len() as uint-1;
        }
    }

    fn restore(&self,mut idx:uint)->Vec<i8>{
        idx=self.nodes[idx as usize].track_id;
        let mut ret=vec![];
        while idx!=!0{
            ret.push(self.track[idx as usize].1);
            idx=self.track[idx as usize].0;
        }
        ret.reverse();
        ret
    }

    fn append_cands(&self,input:&Input,turn:usize,idx:usize,cands:&mut Vec<Cand>){
        let node=&self.nodes[idx];

        let next=|add:i8|->(i16,u64){
            let mut score=node.score;
            let mut hash=node.hash;
            for &n in &input.cmds[turn]{
                score-=input.score[turn][n][node.state[n].abs() as usize];
                let new=node.state[n]+add;
                hash+=add as u64*input.zob[n];
                score+=input.score[turn+1][n][new.abs() as usize];
                score+=(new==0) as i16;
            }
            (score,hash)
        };

        let (eval_score,hash)=next(1);
        let cand=Cand{
            op:1,
            parent:idx as uint,
            eval_score,hash,
        };
        cands.push(cand);

        if turn!=0{
            let (eval_score,hash)=next(-1);
            let cand=Cand{
                op:-1,
                parent:idx as uint,
                eval_score,hash,
            };
            cands.push(cand);
        }
    }
    
    fn solve(&mut self,input:&Input)->Vec<i8>{
        use std::cmp::Reverse;
        let M=MAX_WIDTH;
        
        let mut cands=Vec::<Cand>::with_capacity(MAX_WIDTH);
        let mut set=NopHashSet::default();
        for t in 0..TURN{
            if t!=0{
                if cands.len()>M{
                    cands.select_nth_unstable_by_key(M,|a|Reverse(a.eval_score));
                    cands.truncate(M);
                }
                cands.sort_unstable_by_key(|a|Reverse(a.eval_score));
                set.clear();
                self.update(input,t-1,cands.iter().filter(|cand|
                    set.insert(cand.hash)
                ).take(M).cloned());
            }

            cands.clear();
            self.enum_cands(input,t,&mut cands);
            assert!(!cands.is_empty(),"次の合法手が存在しないよ");
        }

        let best=cands.iter().max_by_key(|a|a.raw_score(input)).unwrap();
        eprintln!("score = {}",best.raw_score(input));

        let mut ret=self.restore(best.parent);
        ret.push(best.op);

        ret
    }
}


#[allow(unused)]
mod nop_hash{
    use std::collections::{HashMap,HashSet};
    use core::hash::BuildHasherDefault;
    use core::hash::Hasher;
    
    #[derive(Default)]
    pub struct NopHasher{
        hash:u64,
    }
    impl Hasher for NopHasher{
        fn write(&mut self,_:&[u8]){
            panic!();
        }
    
        #[inline]
        fn write_u64(&mut self,n:u64){
            self.hash=n;
        }
    
        #[inline]
        fn finish(&self)->u64{
            self.hash
        }
    }
    
    pub type NopHashMap<K,V>=HashMap<K,V,BuildHasherDefault<NopHasher>>;
    pub type NopHashSet<V>=HashSet<V,BuildHasherDefault<NopHasher>>;
}
#[allow(unused)]
use nop_hash::*;



use std::cmp::{self, Ordering, Ordering::*};
use std::mem::{self, MaybeUninit};
use std::ptr;

struct CopyOnDrop<T> {
    src: *const T,
    dest: *mut T,
}

impl<T> Drop for CopyOnDrop<T> {
    fn drop(&mut self) {
        unsafe {
            ptr::copy_nonoverlapping(self.src, self.dest, 1);
        }
    }
}

fn shift_tail<T, F>(v: &mut [T], is_less: &mut F)
where
    F: FnMut(&T, &T) -> bool,
{
    let len = v.len();
    unsafe {
        if len >= 2 && is_less(v.get_unchecked(len - 1), v.get_unchecked(len - 2)) {
            let tmp = mem::ManuallyDrop::new(ptr::read(v.get_unchecked(len - 1)));
            let v = v.as_mut_ptr();
            let mut hole = CopyOnDrop { src: &*tmp, dest: v.add(len - 2) };
            ptr::copy_nonoverlapping(v.add(len - 2), v.add(len - 1), 1);

            for i in (0..len - 2).rev() {
                if !is_less(&*tmp, &*v.add(i)) {
                    break;
                }

                ptr::copy_nonoverlapping(v.add(i), v.add(i + 1), 1);
                hole.dest = v.add(i);
            }
        }
    }
}

fn insertion_sort<T, F>(v: &mut [T], is_less: &mut F)
where
    F: FnMut(&T, &T) -> bool,
{
    for i in 1..v.len() {
        shift_tail(&mut v[..i + 1], is_less);
    }
}

fn partition_in_blocks<T, F>(v: &mut [T], pivot: &T, is_less: &mut F) -> usize
where
    F: FnMut(&T, &T) -> bool,
{
    const BLOCK: usize = 128;

    let mut l = v.as_mut_ptr();
    let mut block_l = BLOCK;
    let mut start_l = ptr::null_mut();
    let mut end_l = ptr::null_mut();
    let mut offsets_l = [MaybeUninit::<u8>::uninit(); BLOCK];

    let mut r = unsafe { l.add(v.len()) };
    let mut block_r = BLOCK;
    let mut start_r = ptr::null_mut();
    let mut end_r = ptr::null_mut();
    let mut offsets_r = [MaybeUninit::<u8>::uninit(); BLOCK];

    fn width<T>(l: *mut T, r: *mut T) -> usize {
        assert!(mem::size_of::<T>() > 0);
        (r as usize - l as usize) / mem::size_of::<T>()
    }

    loop {
        let is_done = width(l, r) <= 2 * BLOCK;

        if is_done {
            let mut rem = width(l, r);
            if start_l < end_l || start_r < end_r {
                rem -= BLOCK;
            }

            if start_l < end_l {
                block_r = rem;
            } else if start_r < end_r {
                block_l = rem;
            } else {
                block_l = rem / 2;
                block_r = rem - block_l;
            }
        }

        if start_l == end_l {
            start_l = offsets_l.as_mut_ptr() as *mut _;
            end_l = start_l;
            let mut elem = l;

            for i in 0..block_l {
                unsafe {
                    *end_l = i as u8;
                    end_l = end_l.offset(!is_less(&*elem, pivot) as isize);
                    elem = elem.offset(1);
                }
            }
        }

        if start_r == end_r {
            start_r = offsets_r.as_mut_ptr() as *mut _;
            end_r = start_r;
            let mut elem = r;

            for i in 0..block_r {
                unsafe {
                    elem = elem.offset(-1);
                    *end_r = i as u8;
                    end_r = end_r.offset(is_less(&*elem, pivot) as isize);
                }
            }
        }

        let count = cmp::min(width(start_l, end_l), width(start_r, end_r));

        if count > 0 {
            macro_rules! left {
                () => {
                    l.offset(*start_l as isize)
                };
            }
            macro_rules! right {
                () => {
                    r.offset(-(*start_r as isize) - 1)
                };
            }

            unsafe {
                let tmp = ptr::read(left!());
                ptr::copy_nonoverlapping(right!(), left!(), 1);

                for _ in 1..count {
                    start_l = start_l.offset(1);
                    ptr::copy_nonoverlapping(left!(), right!(), 1);
                    start_r = start_r.offset(1);
                    ptr::copy_nonoverlapping(right!(), left!(), 1);
                }

                ptr::copy_nonoverlapping(&tmp, right!(), 1);
                mem::forget(tmp);
                start_l = start_l.offset(1);
                start_r = start_r.offset(1);
            }
        }

        if start_l == end_l {
            l = unsafe { l.offset(block_l as isize) };
        }

        if start_r == end_r {
            r = unsafe { r.offset(-(block_r as isize)) };
        }

        if is_done {
            break;
        }
    }

    if start_l < end_l {
        while start_l < end_l {
            unsafe {
                end_l = end_l.offset(-1);
                ptr::swap(l.offset(*end_l as isize), r.offset(-1));
                r = r.offset(-1);
            }
        }
        width(v.as_mut_ptr(), r)
    } else if start_r < end_r {
        while start_r < end_r {
            unsafe {
                end_r = end_r.offset(-1);
                ptr::swap(l, r.offset(-(*end_r as isize) - 1));
                l = l.offset(1);
            }
        }
        width(v.as_mut_ptr(), l)
    } else {
        width(v.as_mut_ptr(), l)
    }
}

fn partition<T, F>(v: &mut [T], pivot: usize, is_less: &mut F) -> (usize, bool)
where
    F: FnMut(&T, &T) -> bool,
{
    let (mid, was_partitioned) = {
        v.swap(0, pivot);
        let (pivot, v) = v.split_at_mut(1);
        let pivot = &mut pivot[0];

        let tmp = mem::ManuallyDrop::new(unsafe { ptr::read(pivot) });
        let _pivot_guard = CopyOnDrop { src: &*tmp, dest: pivot };
        let pivot = &*tmp;

        let mut l = 0;
        let mut r = v.len();

        unsafe {
            while l < r && is_less(v.get_unchecked(l), pivot) {
                l += 1;
            }

            while l < r && !is_less(v.get_unchecked(r - 1), pivot) {
                r -= 1;
            }
        }

        (l + partition_in_blocks(&mut v[l..r], pivot, is_less), l >= r)
    };

    v.swap(0, mid);

    (mid, was_partitioned)
}

fn partition_equal<T, F>(v: &mut [T], pivot: usize, is_less: &mut F) -> usize
where
    F: FnMut(&T, &T) -> bool,
{
    v.swap(0, pivot);
    let (pivot, v) = v.split_at_mut(1);
    let pivot = &mut pivot[0];

    let tmp = mem::ManuallyDrop::new(unsafe { ptr::read(pivot) });
    let _pivot_guard = CopyOnDrop { src: &*tmp, dest: pivot };
    let pivot = &*tmp;

    let mut l = 0;
    let mut r = v.len();
    loop {
        unsafe {
            while l < r && !is_less(pivot, v.get_unchecked(l)) {
                l += 1;
            }

            while l < r && is_less(pivot, v.get_unchecked(r - 1)) {
                r -= 1;
            }

            if l >= r {
                break;
            }

            r -= 1;
            let ptr = v.as_mut_ptr();
            ptr::swap(ptr.add(l), ptr.add(r));
            l += 1;
        }
    }

    l + 1
}

fn choose_pivot<T, F>(v: &mut [T], is_less: &mut F) -> (usize, bool)
where
    F: FnMut(&T, &T) -> bool,
{
    const SHORTEST_MEDIAN_OF_MEDIANS: usize = 50;
    const MAX_SWAPS: usize = 4 * 3;

    let len = v.len();

    let mut a = len / 4 * 1;
    let mut b = len / 4 * 2;
    let mut c = len / 4 * 3;

    let mut swaps = 0;

    if len >= 8 {
        let mut sort2 = |a: &mut usize, b: &mut usize| unsafe {
            if is_less(v.get_unchecked(*b), v.get_unchecked(*a)) {
                ptr::swap(a, b);
                swaps += 1;
            }
        };

        let mut sort3 = |a: &mut usize, b: &mut usize, c: &mut usize| {
            sort2(a, b);
            sort2(b, c);
            sort2(a, b);
        };

        if len >= SHORTEST_MEDIAN_OF_MEDIANS {
            let mut sort_adjacent = |a: &mut usize| {
                let tmp = *a;
                sort3(&mut (tmp - 1), a, &mut (tmp + 1));
            };

            sort_adjacent(&mut a);
            sort_adjacent(&mut b);
            sort_adjacent(&mut c);
        }

        sort3(&mut a, &mut b, &mut c);
    }

    if swaps < MAX_SWAPS {
        (b, swaps == 0)
    } else {
        v.reverse();
        (len - 1 - b, true)
    }
}


fn partition_at_index_loop<'a, T, F>(
    mut v: &'a mut [T],
    mut index: usize,
    is_less: &mut F,
    mut pred: Option<&'a T>,
) where
    F: FnMut(&T, &T) -> bool,
{
    loop {
        const MAX_INSERTION: usize = 10;
        if v.len() <= MAX_INSERTION {
            insertion_sort(v, is_less);
            return;
        }

        let (pivot, _) = choose_pivot(v, is_less);

        if let Some(p) = pred {
            if !is_less(p, &v[pivot]) {
                let mid = partition_equal(v, pivot, is_less);

                if mid > index {
                    return;
                }

                v = &mut v[mid..];
                index = index - mid;
                pred = None;
                continue;
            }
        }

        let (mid, _) = partition(v, pivot, is_less);

        let (left, right) = v.split_at_mut(mid);
        let (pivot, right) = right.split_at_mut(1);
        let pivot = &pivot[0];

        if mid < index {
            v = right;
            index = index - mid - 1;
            pred = Some(pivot);
        } else if mid > index {
            v = left;
        } else {
            return;
        }
    }
}

fn partition_at_index<T, F>(
    v: &mut [T],
    index: usize,
    mut is_less: F,
) -> (&mut [T], &mut T, &mut [T])
where
    F: FnMut(&T, &T) -> bool,
{
    use Greater;
    use Less;

    if index >= v.len() {
        panic!("partition_at_index index {} greater than length of slice {}", index, v.len());
    }

    if mem::size_of::<T>() == 0 {
    } else if index == v.len() - 1 {
        let (max_index, _) = v
            .iter()
            .enumerate()
            .max_by(|&(_, x), &(_, y)| if is_less(x, y) { Less } else { Greater })
            .unwrap();
        v.swap(max_index, index);
    } else if index == 0 {
        let (min_index, _) = v
            .iter()
            .enumerate()
            .min_by(|&(_, x), &(_, y)| if is_less(x, y) { Less } else { Greater })
            .unwrap();
        v.swap(min_index, index);
    } else {
        partition_at_index_loop(v, index, &mut is_less, None);
    }

    let (left, right) = v.split_at_mut(index);
    let (pivot, right) = right.split_at_mut(1);
    let pivot = &mut pivot[0];
    (left, pivot, right)
}


pub trait Nth{
    type T;
    fn select_nth_unstable(&mut self, index: usize) where Self::T: Ord;
    fn select_nth_unstable_by<F: FnMut(&Self::T, &Self::T) -> Ordering>(&mut self, index: usize, compare: F);
    fn select_nth_unstable_by_key<K: Ord, F: FnMut(&Self::T) -> K>(&mut self, index: usize, f: F);
}

impl<T> Nth for [T]{
    type T = T;

    #[inline]
    fn select_nth_unstable(&mut self, index: usize) where T: Ord{
        partition_at_index(self, index, T::lt);
    }

    #[inline]
    fn select_nth_unstable_by<F: FnMut(&T, &T) -> Ordering>(&mut self, index: usize, mut compare: F){
        partition_at_index(self, index, |a: &T, b: &T| compare(a, b) == Less);
    }
    
    #[inline]
    fn select_nth_unstable_by_key<K: Ord, F: FnMut(&T) -> K>(&mut self, index:usize, mut f: F){
        partition_at_index(self, index, |a: &T, b: &T| f(a).lt(&f(b)));
    }
}

提出情報

コンパイルエラー

warning: the item `Greater` is imported redundantly
   --> src/main.rs:679:9
    |
309 | use std::cmp::{self, Ordering, Ordering::*};
    |                                ----------- the item `Greater` is already imported here
...
679 |     use Greater;
    |         ^^^^^^^
    |
    = note: `#[warn(unused_imports)]` on by default

warning: the item `Less` is imported redundantly
   --> src/main.rs:680:9
    |
309 | use std::cmp::{self, Ordering, Ordering::*};
    |                                ----------- the item `Less` is already imported here
...
680 |     use Less;
    |         ^^^^

warning: unused variable: `input`
   --> src/main.rs:118:24
    |
118 |     fn raw_score(&self,input:&Input)->i16{
    |                        ^^^^^ help: consider prefixing with an underscore: `_input`
    |
    = note: `#[warn(unused_variables)]` on by default

ジャッジ結果