local fmt = require "fmt"

local function mcpi(n)
    local inside = 0
    for _ = 1, n do
        local x = math.random()
        local y = math.random()
        if x * x + y * y <= 1 then inside += 1 end
    end
    return 4 * inside / n
end

print("Iterations -> Approx Pi  -> Error%")
print("----------    ----------    ------")
local n = 1000
while n <= 1e8 do
    local pi = mcpi(n)
    local err = math.abs(math.pi - pi) / math.pi * 100.0
    fmt.print("%9d  -> %10.8f -> %6.4f", n, pi, err)
    n *= 10
end