Lua實戰之拆分整數

Description

將指定的整數按規則由大到小拆分成多個更小的整數！

e.g.

被拆分的的整數：23

拆分規則：{1, 2, 3}

拆分結果：7個3，1個2

Implemention

function splitNum(targetNum, ruleTbl)
    if #ruleTbl == 0 then
        return targetNum
    end

    for i = #ruleTbl, 1, -1 do
        local count = math.modf(targetNum / ruleTbl[i])
        if count > 0 then
            print(ruleTbl[i], count)
            targetNum = targetNum % ruleTbl[i]
            if targetNum == 0 then
                break
            end
        end
    end
    if targetNum > 0 then
        print("split failed->", targetNum)
    end    
end

local targetNum = 23
local ruleTbl = {1, 2, 3}
splitNum(targetNum, ruleTbl)
-- 3	7
-- 2	1

Tips

浮點型的數由於精度問題，不能像整數這樣拆分！但是可以先將浮點型的數轉成整數進行拆分，再還原回去即可！