Question

我所拥有的是嵌套表（两级）。我要做的是合并（展平？）子表，任何重复项溢出到新键。所以输入看起来像

t = {
  [1]  = {
    [1] = "One",
    [3] = "Three"
  },
  [2] = {
    [2] = "Two",
    [3] = "Three"
  },
  [3] = {
    [1] = "One",
    [2] = "Two",
    [4] = "Four"
  }
}

，输出看起来像

t = {
  [1] = {
    [1] = "One",
    [2] = "Two",
    [3] = "Three",
    [4] = "Four"
  }  
  [2] = {
    [1] = "One",
    [2] = "Two",
    [3] = "Three"
  }
}

输入表最多可达1000个键，所以我希望它能有效地完成。

Answer 1

试试这个：

local d={}
for k,v in pairs(t) do
    if k~=1 then
        for kk,vv in pairs(v) do
            if t[1][kk]==nil then
                t[1][kk]=vv
            else
                d[kk]=vv
            end
        end
        t[k]=nil
    end
end
t[2]=d

Answer 2

local bottom, max_btm = {}, 0
for top = #t, 1, -1 do
  for k, v in pairs(t[top]) do
    local btm = bottom[k] or 0
    if btm < top then
      repeat btm = btm + 1
      until btm == top or not t[btm][k]
      if btm ~= top then
        t[btm][k], t[top][k] = v
      end
      bottom[k] = btm
      max_btm = math.max(max_btm, btm)
    end
  end
  if max_btm < top then
    t[top] = nil
  end
end

合并表与剩余 - Lua

2 个答案: