------------------------------------------------------------
bubble sort
------------------------------------------------------------

# swaps given two references
def swap(&a, &b) do
    t = a; a = b; b = t
end

# sorts given array and returns it
def bubbleSort(arr: Array) do
    len = arr.length
    for i <- ...len
        nswap = 0
        for j in i+1...len do
            if arr[i] < arr[j] then
                swap arr[i], arr[j]
                nswap += 1
            end
        end
        break if nswap == 0
    end
    arr
end


tests = [
    [6, 10, 8, 3, 5, 7, 4, 2, 12, 1, 11, 9],
    [8, 12, 5, 10, 11, 4, 1, 3, 6, 2, 7, 9],
    [11, 9, 4, 10, 3, 7, 5, 1, 2, 12, 8, 6],
]
results = []

for test <- tests
    result = test.dup
    println tests, " => ", bubbleSort(result)
    results << result
end

puts 'test failed!' if not (results[0] == results[1] == results[2])