AtCoder AGC #015

agc015-a.rb

N, A, B = gets.chomp.split(" ").map(&:to_i)
if N == 1 then
  if A == B then
    puts 1
  else
    puts 0
  end
else
  if A == B then
    puts 1
  elsif A > B then
    puts 0
  else
    puts (B - A) * (N - 2) + 1
  end
end

agc015-b.rb

S = gets.chomp.split("")

n = S.size
ret = 0
(1..n).each do |i|
  if i == 1 || i == n then
    ret += (n - 1)
  else
    if S[i - 1] == "U" then
      ret += ((n - i) + (i - 1) * 2)
    else
      ret += ((n - i) * 2 + (i - 1))
    end
  end
end
puts ret

agc015-c.rb

# http://agc015.contest.atcoder.jp/submissions/1314849
# TLE

N, M, Q = gets.chomp.split(" ").map(&:to_i)

node = []
N.times do
  node << gets.chomp.split("").map(&:to_i)
end

edge_h = Array.new(N){Array.new(M, 0)}
edge_v = Array.new(N){Array.new(M, 0)}

N.times do |i|
  M.times do |j|
    if j + 1 < M then
      edge_h[i][j] = 1 if node[i][j] == 1 && node[i][j+1] == 1
    end
    if i > 0
      edge_v[i][j] = 1 if node[i][j] == 1 && node[i-1][j] == 1
    end
  end
end

cumsum = Array.new(N+1){Array.new(M+1, 0)}
cumsum_h = Array.new(N+1){Array.new(M+1, 0)}
cumsum_v = Array.new(N+1){Array.new(M+1, 0)}

N.times do |i|
  M.times do |j|
    cumsum[i+1][j+1] = node[i][j] + cumsum[i][j+1] + cumsum[i+1][j] - cumsum[i][j]
    cumsum_h[i+1][j+1] = edge_h[i][j] + cumsum_h[i][j+1] + cumsum_h[i+1][j] - cumsum_h[i][j]
    cumsum_v[i+1][j+1] = edge_v[i][j] + cumsum_v[i][j+1] + cumsum_v[i+1][j] - cumsum_v[i][j]
  end
end

Q.times do |v|
  y1, x1, y2, x2 = gets.chomp.split(" ").map{|c| c.to_i}
  sum_node = cumsum[y2][x2] - cumsum[y1-1][x2] - cumsum[y2][x1-1] + cumsum[y1-1][x1-1]
  sum_edge_h = cumsum_h[y2][x2-1] - cumsum_h[y1-1][x2-1] - cumsum_h[y2][x1-1] + cumsum_h[y1-1][x1-1]
  sum_edge_v = cumsum_v[y2][x2] - cumsum_v[y1-1+1][x2] - cumsum_v[y2][x1-1] + cumsum_v[y1-1+1][x1-1]
  puts sum_node - sum_edge_h - sum_edge_v
end