local mapCnt = require("map.count")

---随机元素
---@param tab table<any,any> @表
---@return any,any @key,val
return function(tab)
 local cnt = mapCnt(tab)
 local who = math.random(1, cnt)
 
 for k, v in pairs(tab) do
 who = who - 1
 
 if who <= 0 then
 return k, v
 end
 end
end