next(t)
可以用来检查一个table是否为空
Last active
May 20, 2022 03:46
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Lua集子
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local function pick(rules, count, random_func) | |
random_func = random_func or math.random | |
count = count or 1 | |
local ret = {} | |
local total_weight = 0 | |
for _, v in ipairs(rules) do | |
local weight = v.weight | |
total_weight = total_weight + weight | |
end | |
if total_weight <= 0 then | |
return | |
end | |
local index | |
for i=1, count do | |
local rd = random_func(total_weight) | |
for k, rule in ipairs(rules) do | |
local weight = rule.weight | |
if rd <= weight then | |
table.insert(ret, rule) | |
index = k | |
break | |
else | |
rd = rd - weight | |
end | |
end | |
end | |
return ret, index | |
end | |
local rules = { | |
{ | |
id=1, | |
weight=6000 | |
}, | |
{ | |
id=2, | |
weight=3000 | |
}, | |
{ | |
id=3, | |
weight=1000 | |
} | |
} | |
pick(rules, 1) |
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