This documentation is automatically generated by online-judge-tools/verification-helper
# verification-helper: PROBLEM https://yukicoder.me/problems/no/886 require "../../src/math/gcd" require "../../src/math/mint" h, w = read_line.split.map(&.to_i) hh = (0...h).map { |i| Mint.new h - i } ww = (0...w).map { |i| Mint.new w - i } one = Mint.new(h) * w.pred + Mint.new(w) * h.pred puts GCD.convolution(hh, ww).fetch(1, Mint.zero) * 2 + one
# verification-helper: PROBLEM https://yukicoder.me/problems/no/886 # require "../../src/math/gcd" # require "../../src/math/prime" module Prime extend self include Indexable(Int32) @@primes = [ 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, 509, 521, 523, 541, 547, 557, 563, 569, 571, 577, 587, 593, 599, 601, 607, 613, 617, 619, 631, 641, 643, 647, 653, 659, 661, 673, 677, 683, 691, 701, 709, 719, 727, 733, 739, 743, 751, 757, 761, 769, 773, 787, 797, 809, 811, 821, 823, 827, 829, 839, 853, 857, 859, 863, 877, 881, 883, 887, 907, 911, 919, 929, 937, 941, 947, 953, 967, 971, 977, 983, 991, 997, ] private def generate_primes : Nil size = @@primes.size primes = Array.new(size) { |i| @@primes.last + (i + 1) * 2 } last = primes.last @@primes.each do |prime| next if prime == 2 break if prime * prime > last from = prime * ((@@primes.last // prime + 1) // 2 * 2 + 1) from.step(to: last, by: prime * 2) do |x| primes[~((last - x) // 2)] = 0 end end @@primes.concat primes.reject(0) end private def generate_until(*, index : Int) while @@primes.size <= index generate_primes end end private def generate_until(*, value : Int) while @@primes.last < value generate_primes end end private def check_index_out_of_bounds(index) if 0 <= index < size index else yield end end # Returns the *index* th prime, without doing any bounds check. def unsafe_fetch(index : Int) : Int32 generate_until(index: index) @@primes.unsafe_fetch(index) end # Returns the limit of size. def size : Int32 10**9 end def []?(start : Int, count : Int) : Array(Int32)? raise ArgumentError.new "Negative count: #{count}" if count < 0 return [] of Int32 if start == size if 0 <= start <= size return [] of Int32 if count == 0 count = Math.min(count, size - start) generate_until(index: start + count) Array(Int32).build(count) do |buffer| buffer.copy_from(@@primes.to_unsafe + start, count) count end end end def [](start : Int, count : Int) : Array(Int32) self[start, count]? || raise IndexError.new end private def self.range_to_index_and_count(range : Range, size : Int) end_index = range.end || raise ArgumentError.new end_index -= 1 if range.excludes_end? start_index = range.begin || 0 raise IndexError.new unless start_index >= 0 count = Math.max(end_index - start_index + 1, 0) {start_index, count} end def []?(range : Range) : Array(Int32)? self[*range_to_index_and_count(range, size)]? end def [](range : Range) : Array(Int32) self[*range_to_index_and_count(range, size)] end def includes?(x : Int) : Bool generate_until(value: x) @@primes.bsearch { |y| y >= x } == x end def index(x : Int) : Int32? generate_until(value: x) i = @@primes.bsearch_index { |y| y >= x }.not_nil! @@primes[i] == x ? i : nil end def each(x : Int, &) : Nil i = 0 loop do generate_primes if @@primes.size == i prime = @@primes.unsafe_fetch(i) break if prime > x yield prime i += 1 end end def each(x : Int) each.take_while { |prime| prime <= x } end end class Array(T) # `result[i] = Sum_{n | i} a[i]` (inplace) def gcd_zeta! Prime.each(size - 1) do |p| i, k = size.pred // p, size.pred // p * p while k > 0 self[i] += self[i * p] i -= 1; k -= p end end self end # `result[i] = Sum_{n | i} a[i]` def gcd_zeta dup.gcd_zeta! end # `a[i] = Sum_{n | i} result[i]` (inplace) def gcd_mobius! Prime.each(size - 1) do |p| i, k = 1, p while k < size self[i] -= self[k] i += 1; k += p end end self end # `a[i] = Sum_{n | i} result[i]` def gcd_mobius dup.gcd_mobius! end end module GCD extend self # `result[n] = Sum_{gcd(i, j) = n} f[i] * g[j]` def convolution(f : Array(T), g : Array(T)) forall T f.gcd_zeta.zip?(g.gcd_zeta).map { |x, y| (x || T.zero) * (y || T.zero) }.gcd_mobius! end end # require "../../src/math/mint" struct ModInt(MOD) def self.mod MOD end def self.zero new end def self.raw(value : Int64) result = new result.value = value result end macro [](*nums) Array({{@type}}).build({{nums.size}}) do |buffer| {% for num, i in nums %} buffer[{{i}}] = {{@type}}.new({{num}}) {% end %} {{nums.size}} end end getter value : Int64 private macro check_mod {% if MOD.is_a?(NumberLiteral) %} {% raise "can't instantiate ModInt(MOD) with MOD = #{MOD} (MOD must be positive)" unless MOD >= 1 %} {% raise "can't instantiate ModInt(MOD) with MOD = #{MOD.kind} (MOD must be Int64)" unless MOD.kind == :i64 %} {% else %} {% raise "can't instantiate ModInt(MOD) with MOD = #{MOD.class_name.id} (MOD must be an integer)" %} {% end %} end def initialize check_mod @value = 0i64 end def initialize(value) check_mod @value = value.to_i64 % MOD end def initialize(m : ModInt(MOD2)) forall MOD2 {% raise "Can't create ModInt(#{MOD}) from ModInt(#{MOD2})" if MOD != MOD2 %} check_mod @value = m.value end protected def value=(value : Int64) @value = value end def self.scan(scanner, io : IO) : self new scanner.i64(io) end def ==(m : ModInt(MOD2)) forall MOD2 {% raise "Can't compare ModInt(#{MOD}) and ModInt(#{MOD2})" if MOD != MOD2 %} value == m.value end def ==(m : Int) value == m end def + : self self end def - : self self.class.raw(value != 0 ? MOD &- value : 0i64) end def +(v) self + self.class.new(v) end def +(m : self) x = value &+ m.value x &-= MOD if x >= MOD self.class.raw(x) end def -(v) self - self.class.new(v) end def -(m : self) x = value &- m.value x &+= MOD if x < 0 self.class.raw(x) end def *(v) self * self.class.new(v) end def *(m : self) self.class.new(value &* m.value) end def /(v) self / self.class.new(v) end def /(m : self) raise DivisionByZeroError.new if m.value == 0 a, b, u, v = m.value, MOD, 1i64, 0i64 while b != 0 t = a // b a &-= t &* b a, b = b, a u &-= t &* v u, v = v, u end self.class.new(value &* u) end def //(v) self / v end def **(exponent : Int) t, res = self, self.class.raw(1i64) while exponent > 0 res *= t if exponent & 1 == 1 t *= t exponent >>= 1 end res end {% for op in %w[< <= > >=] %} def {{op.id}}(other) raise NotImplementedError.new({{op}}) end {% end %} def inv self.class.raw(1) // self end def succ self.class.raw(value != MOD &- 1 ? value &+ 1 : 0i64) end def pred self.class.raw(value != 0 ? value &- 1 : MOD &- 1) end def abs self end def abs2 self * self end def to_i64 : Int64 value end def to_s(io : IO) : Nil value.to_s(io) end def inspect(io : IO) : Nil value.inspect(io) end end struct Int def to_m(type : M.class) forall M M.new(self) end end class String def to_m(type : M.class) forall M M.new(self) end end alias Mint = ModInt(1000000007i64) alias Mint2 = ModInt(998244353i64) h, w = read_line.split.map(&.to_i) hh = (0...h).map { |i| Mint.new h - i } ww = (0...w).map { |i| Mint.new w - i } one = Mint.new(h) * w.pred + Mint.new(w) * h.pred puts GCD.convolution(hh, ww).fetch(1, Mint.zero) * 2 + one