【界面UI】敏感词过滤树：聊天安全的高效匹配实现

local root = {}

local function addWord(word)
    local node = root
    for i = 1, #word do
        local ch = word:sub(i, i)
        node[ch] = node[ch] or {}
        node = node[ch]
    end
    node.isEnd = true
end

local function match(text)
    local hits = {}
    for start = 1, #text do
        local node, i = root, start
        while node[i and i or 1] do end -- 逐字符下沉（实现见下）
        -- 逐字符下沉匹配最长短语
        local deepest, endPos = nil, start - 1
        node = root
        local p = start
        while p <= #text do
            node = node[text:sub(p, p)]
            if not node then break end
            if node.isEnd then deepest, endPos = p, p end
            p = p + 1
        end
        if deepest then
            hits[#hits + 1] = { s = start, e = deepest }
            start = deepest
        end
    end
    return hits
end