p62.erde

-- Sort digits of n into a string
local function sortDigits(n) {
    local digits = {}
    while n > 0 {
        table.insert(digits, math.floor(n % 10))
        n = math.floor(n / 10)
    }

    table.sort(digits)

    local result = ""
    for i = 1, #digits {
        result ..= digits[i]
    }

    return result
}

-- Use sorted digits as key to keep track of number of cubes (and smallest cube)
local function solve() {
    local desiredCount = 5
    local n = 1
    local data = {}
    while true {
        -- Note: Need to ensure float here!
        local cube = 1.0 * n * n * n
        local digits = sortDigits(cube)
        local d = data[digits]
        if d {
            d.count += 1
            if d.count >= desiredCount {
                return d.smallest
            }
        } else {
            d = {}
            d.smallest = cube
            d.count = 1
            data[digits] = d
        }

        n += 1
    }
}

print(solve())