結果
問題 | No.1148 土偶Ⅲ |
ユーザー | へのく |
提出日時 | 2020-08-06 21:46:49 |
言語 | Rust (1.77.0 + proconio) |
結果 |
AC
|
実行時間 | 24 ms / 2,000 ms |
コード長 | 26,391 bytes |
コンパイル時間 | 14,702 ms |
コンパイル使用メモリ | 381,740 KB |
実行使用メモリ | 6,080 KB |
最終ジャッジ日時 | 2024-09-21 22:09:03 |
合計ジャッジ時間 | 16,552 ms |
ジャッジサーバーID (参考情報) |
judge4 / judge2 |
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テストケース
テストケース表示入力 | 結果 | 実行時間 実行使用メモリ |
---|---|---|
testcase_00 | AC | 1 ms
5,248 KB |
testcase_01 | AC | 1 ms
5,376 KB |
testcase_02 | AC | 2 ms
5,376 KB |
testcase_03 | AC | 1 ms
5,376 KB |
testcase_04 | AC | 1 ms
5,376 KB |
testcase_05 | AC | 9 ms
5,376 KB |
testcase_06 | AC | 19 ms
5,376 KB |
testcase_07 | AC | 11 ms
5,376 KB |
testcase_08 | AC | 16 ms
5,376 KB |
testcase_09 | AC | 17 ms
5,376 KB |
testcase_10 | AC | 11 ms
5,376 KB |
testcase_11 | AC | 12 ms
5,376 KB |
testcase_12 | AC | 2 ms
5,376 KB |
testcase_13 | AC | 4 ms
5,376 KB |
testcase_14 | AC | 3 ms
5,376 KB |
testcase_15 | AC | 9 ms
5,376 KB |
testcase_16 | AC | 4 ms
5,376 KB |
testcase_17 | AC | 24 ms
6,080 KB |
testcase_18 | AC | 1 ms
5,376 KB |
testcase_19 | AC | 11 ms
5,376 KB |
testcase_20 | AC | 7 ms
5,376 KB |
testcase_21 | AC | 5 ms
5,376 KB |
testcase_22 | AC | 2 ms
5,376 KB |
testcase_23 | AC | 4 ms
5,376 KB |
testcase_24 | AC | 5 ms
5,376 KB |
testcase_25 | AC | 5 ms
5,376 KB |
testcase_26 | AC | 18 ms
5,376 KB |
testcase_27 | AC | 3 ms
5,376 KB |
ソースコード
#![allow(unused_imports, non_snake_case)] #![allow(dead_code)] use crate::{arraylist::List, data_structure::counter::Counter, scanner::Scanner}; fn main() { let mut scan = Scanner::new(); let n = scan.read::<i32>(); let w = scan.read::<i64>(); let a = scan.readn::<i64>(n); let mut sum = 0; let mut right = 0; let mut ret = 0; let mut cnt = Counter::new(); for left in 0..n { while right < n && sum <= w && sum + a[right] <= w && cnt[a[right]] == 0 { sum += a[right]; cnt[a[right]] += 1; right += 1; } chmax!(ret, right - left); if right == left { right += 1; } else { sum -= a[left]; cnt[a[left]] -= 1; } } println!("{}", ret); } pub mod independent { pub mod integer { pub trait Int: std::ops::Add<Output = Self> + std::ops::Sub<Output = Self> + std::ops::Mul<Output = Self> + std::ops::Div<Output = Self> + std::ops::Rem<Output = Self> + std::ops::AddAssign + std::ops::SubAssign + std::ops::MulAssign + std::ops::DivAssign + std::hash::Hash + PartialEq + Eq + PartialOrd + Ord + Copy { fn to_u8(&self) -> u8; fn to_u16(&self) -> u16; fn to_u32(&self) -> u32; fn to_u64(&self) -> u64; fn to_u128(&self) -> u128; fn to_i8(&self) -> i8; fn to_i16(&self) -> i16; fn to_i32(&self) -> i32; fn to_i64(&self) -> i64; fn to_i128(&self) -> i128; fn to_usize(&self) -> usize; fn to_isize(&self) -> isize; fn from_u8(x: u8) -> Self; fn from_u16(x: u16) -> Self; fn from_u32(x: u32) -> Self; fn from_u64(x: u64) -> Self; fn from_u128(x: u128) -> Self; fn from_i8(x: i8) -> Self; fn from_i16(x: i16) -> Self; fn from_i32(x: i32) -> Self; fn from_i64(x: i64) -> Self; fn from_i128(x: i128) -> Self; fn from_usize(x: usize) -> Self; fn from_isize(x: isize) -> Self; fn zero() -> Self; fn one() -> Self; fn next(&self) -> Self { *self + Self::one() } } macro_rules ! impl_integer_functions { ( $ selftpe : ident , $ ( $ tofn : ident , $ fromfn : ident , $ tpe : ident ) ,* ) => { $ ( fn $ tofn ( & self ) -> $ tpe { * self as $ tpe } fn $ fromfn ( x : $ tpe ) -> Self { x as $ selftpe } ) * } ; } macro_rules ! impl_integer { ( $ ( $ tpe : ident ) ,* ) => { $ ( impl Int for $ tpe { impl_integer_functions ! ( $ tpe , to_u8 , from_u8 , u8 , to_u16 , from_u16 , u16 , to_u32 , from_u32 , u32 , to_u64 , from_u64 , u64 , to_u128 , from_u128 , u128 , to_i8 , from_i8 , i8 , to_i16 , from_i16 , i16 , to_i32 , from_i32 , i32 , to_i64 , from_i64 , i64 , to_i128 , from_i128 , i128 , to_usize , from_usize , usize , to_isize , from_isize , isize ) ; fn zero ( ) -> Self { 0 } fn one ( ) -> Self { 1 } } ) * } ; } impl_integer!(u8, u16, u32, u64, u128, i8, i16, i32, i64, i128, usize, isize); } } pub mod scanner { use crate::arraylist::List; use std::io::{stdin, BufReader, Bytes, Read, Stdin}; use std::str::FromStr; macro_rules ! impl_readxn { ( $ name : ident , $ ( $ tpe : ident ) ,+ ) => { pub fn $ name <$ ( $ tpe : FromStr ) ,+> ( & mut self , n : i32 ) -> List < ( $ ( $ tpe ) ,+ ) > { ( 0 .. n ) . map ( | _ | ( $ ( self . read ::<$ tpe > ( ) ) ,+ ) ) . collect ( ) } } ; } pub struct Scanner { buf: Bytes<BufReader<Stdin>>, } impl Scanner { pub fn new() -> Scanner { Scanner { buf: BufReader::new(stdin()).bytes(), } } pub fn read_next<T: FromStr>(&mut self) -> Option<T> { let token = self .buf .by_ref() .map(|c| c.unwrap() as char) .skip_while(|c| c.is_whitespace()) .take_while(|c| !c.is_whitespace()) .collect::<String>(); token.parse::<T>().ok() } pub fn read<T: FromStr>(&mut self) -> T { self.read_next().unwrap() } pub fn readn<T: FromStr>(&mut self, n: i32) -> List<T> { (0..n).map(|_| self.read::<T>()).collect() } pub fn chars(&mut self) -> List<char> { self.read::<String>().chars().collect() } impl_readxn!(read2n, P, Q); impl_readxn!(read3n, P, Q, R); impl_readxn!(read4n, P, Q, R, S); impl_readxn!(read5n, P, Q, R, S, T); } } pub mod ext { pub mod range { use crate::independent::integer::Int; use std::cmp::{max, min}; use std::ops::{Bound, Range, RangeBounds}; pub trait IntRangeBounds<U: Int>: RangeBounds<U> { fn lbopt(&self) -> Option<U> { match self.start_bound() { Bound::Included(x) => Some(*x), Bound::Excluded(x) => Some(*x + U::one()), Bound::Unbounded => None, } } fn ubopt(&self) -> Option<U> { match self.end_bound() { Bound::Included(x) => Some(*x + U::one()), Bound::Excluded(x) => Some(*x), Bound::Unbounded => None, } } #[doc = " inclusive"] fn lower_bound(&self, limit: U) -> U { self.lbopt().map_or(limit, |x| max(limit, x)) } #[doc = " exclusive"] fn upper_bound(&self, limit: U) -> U { self.ubopt().map_or(limit, |x| min(limit, x)) } fn to_harfopen(&self, lb: U, ub: U) -> Range<U> { self.lower_bound(lb)..self.upper_bound(ub) } fn within(&self, mut t: U) -> U { if let Some(x) = self.lbopt() { if t < x { t = x; } } if let Some(x) = self.ubopt() { if x <= t { t = x - U::one(); } } t } fn width(&self) -> U { if self.empty() { U::zero() } else { self.ubopt().unwrap() - self.lbopt().unwrap() } } fn empty(&self) -> bool { self.lbopt().is_none() || self.ubopt().is_none() || !(self.lbopt().unwrap() < self.ubopt().unwrap()) } fn contain_range(&self, inner: &Self) -> bool { (match (self.lbopt(), inner.lbopt()) { (Some(a), Some(b)) => a <= b, (None, _) => true, (Some(_), None) => false, }) && (match (inner.ubopt(), self.ubopt()) { (Some(a), Some(b)) => a <= b, (_, None) => true, (None, Some(_)) => false, }) } fn separate_range(&self, other: &Self) -> bool { if let (Some(a), Some(b)) = (self.ubopt(), other.lbopt()) { if a <= b { return true; } } if let (Some(a), Some(b)) = (other.ubopt(), self.lbopt()) { if a <= b { return true; } } false } fn overlap(&self, other: &Self) -> Range<U> { let left = if let (Some(a), Some(b)) = (self.lbopt(), other.lbopt()) { max(a, b) } else { self.lbopt().or(other.lbopt()).unwrap() }; let right = if let (Some(a), Some(b)) = (self.ubopt(), other.ubopt()) { min(a, b) } else { self.ubopt().or(other.ubopt()).unwrap() }; left..right } } impl<T: ?Sized, U: Int> IntRangeBounds<U> for T where T: RangeBounds<U> {} } } pub mod macros { #[macro_export] macro_rules ! for_ { ( $ init : stmt ; $ cond : expr ; $ incr : expr , $ body : block ) => { $ init while $ cond { $ body $ incr ; } } ; } #[macro_export] #[doc = " chrange!(x, 0..100). 値を返すやつは IntRangeBounds::within"] macro_rules! chrange { ( $ x : expr , $ r : expr ) => {{ let r = $r; match std::ops::RangeBounds::start_bound(&r) { std::ops::Bound::Included(x) => { $crate::chmax!($x, *x); } std::ops::Bound::Excluded(x) => { $crate::chmax!($x, *x + 1); } _ => (), } match std::ops::RangeBounds::end_bound(&r) { std::ops::Bound::Included(x) => { $crate::chmin!($x, *x); } std::ops::Bound::Excluded(x) => { $crate::chmin!($x, *x - 1); } _ => (), } }}; } #[macro_export] macro_rules! chmax { ( $ x : expr , $ y : expr ) => { if $x < $y { $x = $y; true } else { false } }; } #[macro_export] macro_rules! chmin { ( $ x : expr , $ y : expr ) => { if $x > $y { $x = $y; true } else { false } }; } #[macro_export] macro_rules ! min { ( $ a : expr $ ( , ) * ) => { { $ a } } ; ( $ a : expr , $ b : expr $ ( , ) * ) => { { std :: cmp :: min ( $ a , $ b ) } } ; ( $ a : expr , $ ( $ rest : expr ) ,+ $ ( , ) * ) => { { std :: cmp :: min ( $ a , min ! ( $ ( $ rest ) ,+ ) ) } } ; } #[macro_export] macro_rules ! max { ( $ a : expr $ ( , ) * ) => { { $ a } } ; ( $ a : expr , $ b : expr $ ( , ) * ) => { { std :: cmp :: max ( $ a , $ b ) } } ; ( $ a : expr , $ ( $ rest : expr ) ,+ $ ( , ) * ) => { { std :: cmp :: max ( $ a , max ! ( $ ( $ rest ) ,+ ) ) } } ; } #[macro_export] macro_rules ! assign { ( $ arr : ident $ ( [ $ a : expr ] ) + = $ right : expr ) => { assign ! ( $ arr , $ ( [ $ a ] ) + , = , $ right , default ) ; } ; ( $ arr : ident $ ( [ $ a : expr ] ) + += $ right : expr ) => { assign ! ( $ arr , $ ( [ $ a ] ) + , += , $ right , default ) ; } ; ( $ arr : ident $ ( [ $ a : expr ] ) + -= $ right : expr ) => { assign ! ( $ arr , $ ( [ $ a ] ) + , -= , $ right , default ) ; } ; ( $ arr : ident $ ( [ $ a : expr ] ) + |= $ right : expr ) => { assign ! ( $ arr , $ ( [ $ a ] ) + , |= , $ right , default ) ; } ; ( $ arr : ident $ ( [ $ a : expr ] ) + &= $ right : expr ) => { assign ! ( $ arr , $ ( [ $ a ] ) + , &= , $ right , default ) ; } ; ( $ arr : ident $ ( [ $ a : expr ] ) + ^= $ right : expr ) => { assign ! ( $ arr , $ ( [ $ a ] ) + , ^= , $ right , default ) ; } ; ( $ arr : ident $ ( [ $ a : expr ] ) + min $ right : expr ) => { assign ! ( $ arr , $ ( [ $ a ] ) + , ^= , $ right , min ) ; } ; ( $ arr : ident $ ( [ $ a : expr ] ) + max $ right : expr ) => { assign ! ( $ arr , $ ( [ $ a ] ) + , ^= , $ right , max ) ; } ; ( $ arr : expr , [ $ head : expr ] , $ op : tt , $ right : expr , default ) => { let head = $ head ; if ( 0 ..$ arr . ilen ( ) ) . contains ( &$ head ) { let tmp = $ right ; $ arr [ head ] $ op tmp ; } } ; ( $ arr : expr , [ $ head : expr ] , $ op : tt , $ right : expr , min ) => { let head = $ head ; if ( 0 ..$ arr . ilen ( ) ) . contains ( &$ head ) { let tmp = $ right ; $ arr [ head ] = std :: cmp :: min ( $ arr [ head ] , tmp ) ; } } ; ( $ arr : expr , [ $ head : expr ] , $ op : tt , $ right : expr , max ) => { let head = $ head ; if ( 0 ..$ arr . ilen ( ) ) . contains ( &$ head ) { let tmp = $ right ; $ arr [ head ] = std :: cmp :: max ( $ arr [ head ] , tmp ) ; } } ; ( $ arr : expr , [ $ head : expr ] $ ( [ $ a : expr ] ) +, $ op : tt , $ right : expr , $ kind : ident ) => { let head = $ head ; if ( 0 ..$ arr . ilen ( ) ) . contains ( &$ head ) { assign ! ( $ arr [ head ] , $ ( [ $ a ] ) +, $ op , $ right , $ kind ) ; } } ; } #[macro_export] macro_rules! unwrap { ( $ arg : expr ) => {{ let tmp = $arg; if tmp.is_none() { return; } tmp.unwrap() }}; } #[macro_export] macro_rules! swap { ( $ a : expr , $ b : expr ) => { let tmp = $a; $a = $b; $b = tmp; }; } } pub mod arraylist { use crate::{ext::range::IntRangeBounds, independent::integer::Int}; use std::fmt::Formatter; use std::iter::FromIterator; use std::ops::{Index, IndexMut, RangeBounds}; use std::slice::Iter; #[derive(Clone, PartialEq, Eq)] pub struct List<T> { pub vec: Vec<T>, } impl<T> List<T> { #[inline] pub fn new() -> List<T> { List { vec: vec![] } } #[inline] pub fn init(init: T, n: i32) -> List<T> where T: Clone, { List { vec: vec![init; n as usize], } } #[inline] pub fn from_vec(vec: Vec<T>) -> List<T> { List { vec } } #[inline] pub fn acc<'a, S>(n: i32, mut f: S) -> List<T> where S: FnMut(i32) -> T + 'a, { (0..n).map(|i| f(i)).collect() } #[inline] pub fn ilen(&self) -> i32 { self.vec.len() as i32 } #[inline] pub fn iter(&self) -> Iter<'_, T> { self.vec.iter() } #[inline] pub fn push(&mut self, item: T) { self.vec.push(item); } #[inline] pub fn sort(&mut self) where T: Ord, { self.vec.sort(); } #[inline] pub fn reverse(&mut self) { self.vec.reverse(); } #[inline] pub fn sort_by<F>(&mut self, compare: F) where F: FnMut(&T, &T) -> std::cmp::Ordering, { self.vec.sort_by(compare) } #[inline] pub fn sort_by_key<K, F>(&mut self, compare: F) where F: FnMut(&T) -> K, K: Ord, { self.vec.sort_by_key(compare) } #[inline] pub fn first(&self) -> Option<&T> { self.vec.first() } #[inline] pub fn last(&self) -> Option<&T> { self.vec.last() } #[inline] pub fn pop(&mut self) -> Option<T> { self.vec.pop() } #[inline] pub fn swap(&mut self, i: i32, j: i32) { self.vec.swap(i as usize, j as usize); } #[inline] pub fn append(&mut self, mut other: Self) { self.vec.append(&mut other.vec); } #[inline] pub fn extend(&mut self, other: impl Iterator<Item = T>) { self.vec.extend(other); } #[inline] pub fn mrr(&self) -> std::iter::Cloned<Iter<T>> where T: Clone, { self.iter().cloned() } #[inline] pub fn join(&self, sep: &str) -> String where T: std::fmt::Display, { self.iter() .map(|x| format!("{}", x)) .collect::<Vec<_>>() .join(sep) } #[inline] pub fn map<B, F>(&self, f: F) -> List<B> where T: Clone, F: FnMut(T) -> B, { self.mrr().map(f).collect() } #[inline] pub fn filter<P>(&self, predicate: P) -> List<T> where T: Clone, P: FnMut(&T) -> bool, { self.mrr().filter(predicate).collect() } #[inline] pub fn filter_map<B, F>(&self, f: F) -> List<B> where T: Clone, F: FnMut(T) -> Option<B>, { self.mrr().filter_map(f).collect() } #[doc = " |acc, x| -> acc"] #[inline] pub fn fold<B, F>(&self, init: B, f: F) -> B where T: Clone, F: FnMut(B, T) -> B, { self.mrr().fold(init, f) } #[inline] pub fn any<P>(&self, predicate: P) -> bool where P: FnMut(&T) -> bool, { self.iter().any(predicate) } #[inline] pub fn all<P>(&self, predicate: P) -> bool where P: FnMut(&T) -> bool, { self.iter().all(predicate) } #[inline] pub fn sum(&self) -> T where T: Int, { self.iter().cloned().fold(T::zero(), |acc, x| acc + x) } #[inline] pub fn enumerate(&self) -> List<(i32, T)> where T: Clone, { self.mrr().enumerate().map(|p| (p.0 as i32, p.1)).collect() } #[inline] pub fn find<P>(&self, mut predicate: P) -> Option<&T> where P: FnMut(&T) -> bool, { self.iter().find(|x| predicate(*x)) } #[inline] pub fn index_of<P>(&self, mut predicate: P) -> Option<i32> where P: FnMut(&T) -> bool, { self.iter() .enumerate() .find(|&(_i, x)| predicate(x)) .map(|p| p.0 as i32) } #[inline] pub fn to<B: FromIterator<T>>(&self) -> B where T: Clone, { self.mrr().collect() } #[inline] pub fn min(&self) -> Option<&T> where T: Ord, { self.iter().min() } #[inline] pub fn max(&self) -> Option<&T> where T: Ord, { self.iter().max() } #[inline] pub fn argmin(&self) -> Option<i32> where T: Ord, { let item = self.iter().min()?; self.iter() .enumerate() .find(|p| p.1 == item) .map(|p| p.0 as i32) } #[inline] pub fn argmax(&self) -> Option<i32> where T: Ord, { let item = self.iter().max()?; self.iter() .enumerate() .find(|p| p.1 == item) .map(|p| p.0 as i32) } #[inline] pub fn part<U>(&self, range: U) -> List<T> where T: Clone, U: RangeBounds<i32>, { List::from_vec( self.vec[range.lower_bound(0) as usize..range.upper_bound(self.ilen()) as usize] .to_vec(), ) } #[inline] pub fn first_exn(&self) -> &T { self.first().unwrap() } #[inline] pub fn last_exn(&self) -> &T { self.last().unwrap() } #[inline] pub fn pop_exn(&mut self) -> T { self.pop().unwrap() } #[inline] pub fn min_exn(&self) -> &T where T: Ord, { self.min().unwrap() } #[inline] pub fn max_exn(&self) -> &T where T: Ord, { self.max().unwrap() } #[inline] pub fn argmin_exn(&self) -> i32 where T: Ord, { self.argmin().unwrap() } #[inline] pub fn argmax_exn(&self) -> i32 where T: Ord, { self.argmax().unwrap() } #[inline] pub fn find_exn<P>(&self, predicate: P) -> &T where P: FnMut(&T) -> bool, { self.find(predicate).unwrap() } #[inline] pub fn index_of_exn<P>(&self, predicate: P) -> i32 where P: FnMut(&T) -> bool, { self.index_of(predicate).unwrap() } } impl<T> std::ops::BitXorAssign<T> for List<T> { #[inline] fn bitxor_assign(&mut self, rhs: T) { self.push(rhs); } } impl<T> Index<i32> for List<T> { type Output = T; #[inline] fn index(&self, index: i32) -> &Self::Output { if cfg!(debug_assertions) { self.vec.index(index as usize) } else { unsafe { self.vec.get_unchecked(index as usize) } } } } impl<T> IndexMut<i32> for List<T> { #[inline] fn index_mut(&mut self, index: i32) -> &mut Self::Output { if cfg!(debug_assertions) { self.vec.index_mut(index as usize) } else { unsafe { self.vec.get_unchecked_mut(index as usize) } } } } impl<T> FromIterator<T> for List<T> { fn from_iter<U: IntoIterator<Item = T>>(iter: U) -> Self { List { vec: iter.into_iter().collect(), } } } impl<T> IntoIterator for List<T> { type Item = T; type IntoIter = std::vec::IntoIter<T>; fn into_iter(self) -> std::vec::IntoIter<T> { self.vec.into_iter() } } impl<'a, T> IntoIterator for &'a List<T> { type Item = &'a T; type IntoIter = Iter<'a, T>; fn into_iter(self) -> Iter<'a, T> { self.vec.iter() } } impl<T: std::fmt::Display> std::fmt::Display for List<T> { fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result { write!( f, "{}", self.iter() .map(|x| format!("{}", x)) .collect::<Vec<_>>() .join(" ") ) } } impl<T: std::fmt::Debug> std::fmt::Debug for List<T> { fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result { write!( f, "[{}]", self.iter() .map(|x| format!("{:?}", x)) .collect::<Vec<_>>() .join(", ") ) } } impl<T> From<Vec<T>> for List<T> { fn from(vec: Vec<T>) -> Self { Self::from_vec(vec) } } impl<T: Clone> From<&[T]> for List<T> { fn from(slice: &[T]) -> Self { slice.iter().cloned().collect() } } #[macro_export] macro_rules ! list { ( ) => { $ crate :: arraylist :: List :: new ( ) } ; ( $ ( $ v : expr ) ,+ $ ( , ) ? ) => { $ crate :: arraylist :: List :: from_vec ( [ $ ( $ v ) ,+ ] . to_vec ( ) ) } ; ( $ v : expr ; $ a : expr ) => { $ crate :: arraylist :: List :: init ( $ v , $ a ) } ; ( $ v : expr ; $ a : expr ; $ ( $ rest : expr ) ;+ ) => { $ crate :: arraylist :: List :: init ( list ! ( $ v ; $ ( $ rest ) ;+ ) , $ a ) } ; } } pub mod data_structure { pub mod counter { use std::collections::HashMap; use std::hash::Hash; use std::ops::*; #[derive(Clone, Debug)] pub struct Counter<K: Eq + Hash> { pub cnt: HashMap<K, i64>, pub d: i64, } impl<K: Eq + Hash> Counter<K> { pub fn new() -> Counter<K> { Counter { cnt: HashMap::new(), d: 0, } } #[doc = " Remove key when the value <= 0"] pub fn dec(&mut self, key: K, delta: i64) { if self.by_ref(&key) - delta <= 0 { self.remove(&key); } else { *self.cnt.get_mut(&key).unwrap() -= delta; } } pub fn by_ref(&self, key: &K) -> i64 { *self.cnt.get(key).unwrap_or(&self.d) } pub fn ilen(&self) -> i32 { self.cnt.len() as i32 } } impl<K: Eq + Hash> Deref for Counter<K> { type Target = HashMap<K, i64>; fn deref(&self) -> &Self::Target { &self.cnt } } impl<K: Eq + Hash> DerefMut for Counter<K> { fn deref_mut(&mut self) -> &mut Self::Target { &mut self.cnt } } impl<K: Eq + Hash> Index<K> for Counter<K> { type Output = i64; fn index(&self, index: K) -> &Self::Output { self.cnt.get(&index).unwrap_or(&self.d) } } impl<K: Eq + Hash + Clone> IndexMut<K> for Counter<K> { fn index_mut(&mut self, index: K) -> &mut i64 { if !self.cnt.contains_key(&index) { self.cnt.insert(index.clone(), self.d); } self.cnt.get_mut(&index).unwrap() } } impl<K: Eq + Hash> std::iter::FromIterator<K> for Counter<K> { fn from_iter<T: IntoIterator<Item = K>>(iter: T) -> Self { let mut cnt = HashMap::new(); for i in iter { *cnt.entry(i).or_insert(0) += 1; } Counter { cnt, d: 0 } } } impl<T: Eq + Hash + Clone> Add for Counter<T> { type Output = Counter<T>; fn add(self, other: Counter<T>) -> Counter<T> { let mut ret = Counter::new(); for (k, v) in self.iter().chain(other.iter()) { ret[k.clone()] += *v; } ret } } impl<T: Eq + Hash + Clone> AddAssign for Counter<T> { fn add_assign(&mut self, other: Self) { *self = self.clone().add(other); } } } }