# A join (research 124's suite): customers with ids drawn by MINSTD from
# seed 1 (sparse, distinct), each in one of 16 regions; orders each of a
# customer drawn by index and an amount; the amounts summed by the region of
# each order's customer, found by its id.
record Customer {
  id = 0
  region = 0
}
record Total {
  region = 0
  amount = 0
}
state top = 0
state sum = 0
input go = message {
  customers: u32
  orders: u32
}
on go {
  let all: list of Customer
  let byid: list of Customer by id
  let x = 1
  for i in 0 .. go.customers {
    x = x * 48271 - floor(x * 48271 / 2147483647) * 2147483647
    all.append(Customer { id: x, region: i - floor(i / 16) * 16 })
    byid.add(Customer { id: x, region: i - floor(i / 16) * 16 })
  }
  let totals: list of Total by region
  for r in 0 .. 16 {
    totals.add(Total { region: r })
  }
  for o in 0 .. go.orders {
    x = x * 48271 - floor(x * 48271 / 2147483647) * 2147483647
    let c = all.first + (x - floor(x / go.customers) * go.customers)
    let region = byid[c.id].region
    totals[region].amount = totals[region].amount + (x - floor(x / 1000) * 1000)
  }
  let most = 0
  let all_amounts = 0
  for t in totals {
    most = max(most, t.amount)
    all_amounts = all_amounts + t.amount
  }
  top = most
  sum = all_amounts
}