Lua字符频率：一次扫描的计数表统计

local function freq(s)
    local counts = {}
    for ch in s:gmatch("%a") do
        counts[ch] = (counts[ch] or 0) + 1
    end
    return counts
end

local function topChar(s)
    local counts = freq(s)
    local bestC, bestN = "", 0
    for c, n in pairs(counts) do
        if n > bestN then bestC, bestN = c, n end
    end
    return bestC, bestN
end
local p = getplayerbyname("stat02")
local c, n = topChar("luaengineandm2engine")
sendmsg(p, 1, "最高频 " .. c .. " 出现 " .. n .. " 次")