ac-library.cr

This is not an officially supported Google product.

ac-library.cr is a Crystal port of ac-library.

This library aims to provide the almost-equivalent (and additional) functionality with ac-library but in the manner of Crystal.

ModInt.cr (<atcoder/modint>)

• modint => Unimplemented

• modint998244353 => AtCoder::ModInt998244353

• modint1000000007 => AtCoder::ModInt1000000007

  alias Mint = AtCoder::ModInt1000000007
  Mint.new(30_i64) // Mint.new(7_i64) #=> 285714292

• static_modint => AtCoder.static_modint

  AtCoder.static_modint(ModInt101, 101_i64)
  alias Mint = AtCoder::ModInt101
  Mint.new(80_i64) + Mint.new(90_i64) #=> 89

• dynamic_modint => Unimplemented

FenwickTree.cr (<atcoder/fenwicktree>)

• fenwick_tree<T> fw(n) => AtCoder::FenwickTree(T).new(n)

• fenwick_tree<T> fw(array) => AtCoder::FenwickTree(T).new(array)

  tree = AtCoder::FenwickTree(Int64).new(10)
  tree.add(3, 10)
  tree.add(5, 20)
  tree[3..5] #=> 30
  tree[3...5] #=> 10

  • .add(p, x) => #add(p, x)
  • .sum(l, r) => #[](l...r)

SegTree.cr (<atcoder/segtree>)

• segtree<S, op, e> seg(v) => AtCoder::SegTree(S).new(v, &op?)

  単位元は暗黙的にnilで定義されるため使用する際に定義する必要はありません。逆に言えばモノイドの (単位元以外の) 元にnilを含めることはできません。 The identity element will be implicitly defined as nil, so you don't have to manually define it. In the other words, you cannot include nil into an element of the monoid.

  tree = AtCoder::SegTree.new((0...100).to_a) {|a, b| [a, b].min}
  tree[10...50] #=> 10

  • .set(p, x) => #[]=(p, x)
  • .get(p) => #[](p)
  • .prod(l, r) => #[](l...r)
  • .all_prod() => #all_prod
  • .max_right<f>(l) => Unimplemented
  • .max_left<f>(r) => Unimplemented

LazySegTree.cr (<atcoder/lazysegtree>)

• lazy_segtree<S, op, e, F, mapping, composition, id> seg(v) => AtCoder::LazySegTree(S, F).new(v, op, mapping, composition)

  単位元は暗黙的にnilで定義されるため使用する際に定義する必要はありません。逆に言えばモノイドの (単位元以外の) 元にnilを含めることはできません。 The identity element will be implicitly defined as nil, so you don't have to manually define it. In the other words, you cannot include nil into an element of the monoid.

  また、恒等写像は暗黙的にnilで定義されるため使用する際に定義する必要はありません。逆に言えばFの (恒等写像以外の) 元にnilを含めることはできません。 Similarly, the identity map of F will be implicitly defined as nil, so you don't have to manually define it. In the other words, you cannot include nil into an element of the set F.

  op = ->(a : Int32, b : Int32) { [a, b].min }
  mapping = ->(f : Int32, x : Int32) { f }
  composition = ->(a : Int32, b : Int32) { a }
  tree = AtCoder::LazySegTree(Int32, Int32).new((0...100).to_a, op, mapping, composition)
  tree[10...50] #=> 10
  tree[20...60] = 0
  tree[50...80] #=> 0

  • .set(p, x) => Unimplemented
  • .get(p) => #[](p)
  • .prod(l, r) => #[](l...r)
  • .all_prod() => #all_prod
  • .apply(p, f) => #[]=(p, f)
  • .apply(l, r, f) => #[]=(l...r, f)
  • .max_right<f>(l) => Unimplemented
  • .max_left<f>(r) => Unimplemented

DSU.cr (<atcoder/dsu>)

• dsu(n) => AtCoder::DSU.new(n)

  dsu = AtCoder::DSU.new(10)
  dsu.merge(0, 2)
  dsu.merge(4, 2)
  dsu.same(0, 4) #=> true
  dsu.size(4) #=> 3

  • .merge(a, b) => #merge(a, b)

  • .same(a, b) => #same(a, b)

  • .leader(a) => #leader(a)

  • .size() => #size

  • .groups() => #groups

    • This method returns set instead of list.

MaxFlow.cr (<atcoder/maxflow>)

• mf_graph<Cap> graph(n) => AtCoder::MaxFlow.new(n)

  Cap is always Int64.

  mf = AtCoder::MaxFlow.new(3)
  mf.add_edge(0, 1, 3)
  mf.add_edge(1, 2, 1)
  mf.add_edge(0, 2, 2)
  mf.flow(0, 2) #=> 3

  • .add_edge(from, to, cap) => #add_edge(from, to, cap)
  • .flow(s, t) => #flow(s, t)
  • .min_cut(s) => Unimplemented
  • .get_edge(i) => Unimplemented
  • .edges() => Unimplemented
  • .change_edge(i, new_cap, new_flow) => Unimplemented

SCC.cr (<atcoder/scc>)

• scc_graph graph(n) => AtCoder::SCC.new(n)

  scc = AtCoder::SCC.new(3_i64)
  scc.add_edge(0, 1)
  scc.add_edge(1, 0)
  scc.add_edge(2, 0)
  scc.scc #=> [Set{2}, Set{0, 1}]

  • .add_edge(from, to) => #add_edge(from, to)
  • .scc() => #scc

TwoSat.cr (<atcoder/twosat>)

• two_sat graph(n) => AtCoder::SCC.new(n)

  twosat = AtCoder::TwoSat.new(2_i64)
  twosat.add_clause(0, true, 1, false)
  twosat.add_clause(1, true, 0, false)
  twosat.add_clause(0, false, 1, false)
  twosat.satisfiable? #=> true
  twosat.answer #=> [false, false]

  • .add_clause(i, f, j, g) => #add_clause(i, f, j, g)

  • .satisfiable() => #satisfiable?

  • .answer() => #answer

    This method will raise if it's not satisfiable

Math.cr (<atcoder/math>)

• pow_mod(x, n, m) => AtCoder::Math.pow_mod(x, n, m)
• inv_mod(x, m) => AtCoder::Math.inv_mod(x, m)
• crt(r, m) => AtCoder::Math.crt(r, m)
• floor_sum => AtCoder::Math.floor_sum(n, m, a, b)

PriorityQueue.cr (not in ACL)

• AtCoder::PriorityQueue(T).new

  q = AtCoder::PriorityQueue(Int64).new
  q << 1_i64
  q << 3_i64
  q << 2_i64
  q.pop #=> 3
  q.pop #=> 2
  q.pop #=> 1

  • #<<(v : T)

    Push value into the queue.

  • #pop

    Pop value from the queue.

  • #size

    Returns size of the queue

Prime.cr (not in ACL)

• AtCoder::Prime (module)

  Implements Ruby's Prime library.

  AtCoder::Prime.first(7) # => [2, 3, 5, 7, 11, 13, 17]