local mfl, mce = math.floor, math.ceil local mmi, mma = math.min, math.max local bls, brs = bit.lshift, bit.rshift local SegTree = {} SegTree.updateAll = function(self) for i = self.stagenum - 1, 1, -1 do local cnt = bls(1, i - 1) for j = 1, cnt do self.stage[i][j] = self.func(self.stage[i + 1][j * 2 - 1], self.stage[i + 1][j * 2]) end end end SegTree.create = function(self, n, func, emptyvalue) self.func, self.emptyvalue = func, emptyvalue local stagenum, mul = 1, 1 self.stage = {{}} while mul < n do mul, stagenum = mul * 2, stagenum + 1 self.stage[stagenum] = {} end self.stagenum = stagenum for i = 1, mul do self.stage[stagenum][i] = emptyvalue end self:updateAll() end SegTree.getRange = function(self, left, right) if left == right then return self.stage[self.stagenum][left] end local stagenum = self.stagenum local ret = self.emptyvalue while left <= right do local stage, sz = 1, bls(1, stagenum - 1) local len = right - left + 1 while (left - 1) % sz ~= 0 or len < sz do stage, sz = stage + 1, brs(sz, 1) end ret = self.func(ret, self.stage[stage][1 + brs(left - 1, stagenum - stage)]) left = left + sz end return ret end SegTree.setValue = function(self, idx, value, silent) self.stage[self.stagenum][idx] = value if not silent then for i = self.stagenum - 1, 1, -1 do local dst = brs(idx + 1, 1) local rem = dst * 4 - 1 - idx self.stage[i][dst] = self.func(self.stage[i + 1][idx], self.stage[i + 1][rem]) idx = dst end end end SegTree.new = function(n, func, emptyvalue) local obj = {} setmetatable(obj, {__index = SegTree}) obj:create(n, func, emptyvalue) return obj end local n = io.read("*n") local edge = {} local edgecost = {} local asked = {} local cpos = {} local len = {} local cost = {} local stpos = {} for i = 1, n do edge[i] = {} edgecost[i] = {} asked[i] = false cpos[i] = 0 len[i] = 0 cost[i] = 0 stpos[i] = 0 end len[n + 1] = 1000000007 for i = 1, n - 1 do local x, y, c = io.read("*n", "*n", "*n") x, y = x + 1, y + 1 table.insert(edge[x], y) table.insert(edge[y], x) table.insert(edgecost[x], c) table.insert(edgecost[y], c) end local st = SegTree.new(2 * n - 1, function(a, b) return len[a] < len[b] and a or b end, n + 1) local tasks = {1} local sti = 1 while 0 < #tasks do local src = tasks[#tasks] table.remove(tasks) asked[src] = true stpos[src] = sti st:setValue(sti, src, true) sti = sti + 1 while cpos[src] < #edge[src] do cpos[src] = cpos[src] + 1 local dst = edge[src][cpos[src]] if not asked[dst] then len[dst] = len[src] + 1 cost[dst] = cost[src] + edgecost[src][cpos[src]] table.insert(tasks, src) table.insert(tasks, dst) break end end end st:updateAll() local function solve(x, y, z) local xp, yp, zp = stpos[x], stpos[y], stpos[z] local xyroot = xp < yp and st:getRange(xp, yp) or st:getRange(yp, xp) local xzroot = xp < zp and st:getRange(xp, zp) or st:getRange(zp, xp) local yzroot = yp < zp and st:getRange(yp, zp) or st:getRange(zp, yp) local ret = cost[x] + cost[y] + cost[z] ret = ret - cost[xyroot] - cost[yzroot] - cost[xzroot] print(ret) end local q = io.read("*n") for iq = 1, q do local x, y, z = io.read("*n", "*n", "*n") x, y, z = x + 1, y + 1, z + 1 solve(x, y, z) end