// 子树异或和/子树删除 package main import ( "bufio" "fmt" "math/bits" "os" ) func main() { // https: //yukicoder.me/problems/no/1790 in := bufio.NewReader(os.Stdin) out := bufio.NewWriter(os.Stdout) defer out.Flush() var n int fmt.Fscan(in, &n) tree := NewTree(n) data := make([]E, n-1) for i := 0; i < n-1; i++ { var u, v, xor int fmt.Fscan(in, &u, &v, &xor) u-- v-- tree.AddEdge(u, v, xor) data[i] = E{xor: xor} } tree.Build(0) LM := NewLazyTreeMonoid(tree, data, false) var q int fmt.Fscan(in, &q) for i := 0; i < q; i++ { var op, root int fmt.Fscan(in, &op, &root) root-- if op == 1 { // 删除以root为根的子树(打标记) LM.UpdateSubtree(root, E{removed: true}) if root != 0 { LM.UpdatePath(root, tree.Parent[root], E{removed: true}) } } else { // 查询以root为根的子树的异或和 fmt.Fprintln(out, LM.QuerySubtree(root).xor) } } } const INF = 1e18 type E = struct { xor int removed bool } type Id = E func e() E { return E{} } func id() Id { return E{} } func op(e1, e2 E) E { if e1.removed { return e2 } if e2.removed { return e1 } return E{xor: e1.xor ^ e2.xor} } func mapping(f Id, g E) E { if f.removed || g.removed { return E{removed: true} } return E{xor: f.xor ^ g.xor} } func composition(f, g Id) Id { if f.removed || g.removed { return E{removed: true} } return E{xor: f.xor ^ g.xor} } type LazyTreeMonoid struct { tree *Tree n int unit E isVertex bool seg *_LST } // !树的路径查询 + 区间修改, 维护的量需要满足幺半群的性质,且必须要满足交换律. // data: 顶点的值, 或者边的值.(边的编号为两个定点中较深的那个点的编号) // isVertex: data是否为顶点的值以及查询的时候是否是顶点权值. func NewLazyTreeMonoid(tree *Tree, data []E, isVertex bool) *LazyTreeMonoid { n := len(tree.Tree) res := &LazyTreeMonoid{tree: tree, n: n, unit: e(), isVertex: isVertex} leaves := make([]E, n) if isVertex { for v := range leaves { leaves[tree.LID[v]] = data[v] } } else { for i := range leaves { leaves[i] = res.unit } for e := 0; e < n-1; e++ { v := tree.EidtoV(e) leaves[tree.LID[v]] = data[e] } } res.seg = _NewLST(leaves, e, id, op, mapping, composition) return res } // 第i个顶点或者第i条边的值修改为e. func (tm *LazyTreeMonoid) Set(i int, e E) { if !tm.isVertex { i = tm.tree.EidtoV(i) } i = tm.tree.LID[i] tm.seg.Set(i, e) } func (tm *LazyTreeMonoid) Get(i int) E { return tm.seg.Get(tm.tree.LID[i]) } func (tm *LazyTreeMonoid) UpdatePath(start, target int, lazy Id) { path := tm.tree.GetPathDecomposition(start, target, tm.isVertex) for _, ab := range path { left, right := ab[0], ab[1] if left > right { left, right = right, left } tm.seg.Update(left, right+1, lazy) } } // 查询 start 到 target 的路径上的值.(点权/边权 由 isVertex 决定) func (tm *LazyTreeMonoid) QueryPath(start, target int) E { path := tm.tree.GetPathDecomposition(start, target, tm.isVertex) val := tm.unit for _, ab := range path { a, b := ab[0], ab[1] var x E if a <= b { x = tm.seg.Query(a, b+1) } else { x = tm.seg.Query(b, a+1) } val = op(val, x) } return val } // 找到路径上最后一个 x 使得 QueryPath(start,x) 满足check函数.不存在返回-1. func (tm *LazyTreeMonoid) MaxPath(check func(E) bool, start, target int) int { if !tm.isVertex { return tm._maxPathEdge(check, start, target) } if !check(tm.QueryPath(start, start)) { return -1 } path := tm.tree.GetPathDecomposition(start, target, tm.isVertex) val := tm.unit for _, ab := range path { a, b := ab[0], ab[1] var x E if a <= b { x = tm.seg.Query(a, b+1) } else { x = tm.seg.Query(b, a+1) } if tmp := op(val, x); check(tmp) { val = tmp start = tm.tree.idToNode[b] continue } checkTmp := func(x E) bool { return check(op(val, x)) } if a <= b { i := tm.seg.MaxRight(a, checkTmp) if i == a { return start } return tm.tree.idToNode[i-1] } else { i := tm.seg.MinLeft(a+1, checkTmp) if i == a+1 { return start } return tm.tree.idToNode[i] } } return target } func (tm *LazyTreeMonoid) QuerySubtree(root int) E { l, r := tm.tree.LID[root], tm.tree.RID[root] offset := 1 if tm.isVertex { offset = 0 } return tm.seg.Query(l+offset, r) } func (tm *LazyTreeMonoid) UpdateSubtree(root int, lazy Id) { l, r := tm.tree.LID[root], tm.tree.RID[root] offset := 1 if tm.isVertex { offset = 0 } tm.seg.Update(l+offset, r, lazy) } func (tm *LazyTreeMonoid) QueryAll() E { return tm.seg.QueryAll() } func (tm *LazyTreeMonoid) _maxPathEdge(check func(E) bool, u, v int) int { lca := tm.tree.LCA(u, v) path := tm.tree.GetPathDecomposition(u, lca, tm.isVertex) val := tm.unit // climb for _, ab := range path { a, b := ab[0], ab[1] x := tm.seg.Query(b, a+1) if tmp := op(val, x); check(tmp) { val = tmp u = tm.tree.Parent[tm.tree.idToNode[b]] continue } checkTmp := func(x E) bool { return check(op(val, x)) } i := tm.seg.MinLeft(a+1, checkTmp) if i == a+1 { return u } return tm.tree.Parent[tm.tree.idToNode[i]] } // down path = tm.tree.GetPathDecomposition(lca, v, tm.isVertex) for _, ab := range path { a, b := ab[0], ab[1] x := tm.seg.Query(a, b+1) if tmp := op(val, x); check(tmp) { val = tmp u = tm.tree.idToNode[b] continue } checkTmp := func(x E) bool { return check(op(val, x)) } i := tm.seg.MaxRight(a, checkTmp) if i == a { return u } return tm.tree.idToNode[i-1] } return v } type Tree struct { Tree [][][2]int // (next, weight) Edges [][3]int // (u, v, w) Depth, DepthWeighted []int Parent []int LID, RID []int // 欧拉序[in,out) idToNode []int top, heavySon []int timer int } func NewTree(n int) *Tree { tree := make([][][2]int, n) lid := make([]int, n) rid := make([]int, n) idToNode := make([]int, n) top := make([]int, n) // 所处轻/重链的顶点(深度最小),轻链的顶点为自身 depth := make([]int, n) // 深度 depthWeighted := make([]int, n) parent := make([]int, n) // 父结点 heavySon := make([]int, n) // 重儿子 edges := make([][3]int, 0, n-1) for i := range parent { parent[i] = -1 } return &Tree{ Tree: tree, Depth: depth, DepthWeighted: depthWeighted, Parent: parent, LID: lid, RID: rid, idToNode: idToNode, top: top, heavySon: heavySon, Edges: edges, } } // 添加无向边 u-v, 边权为w. func (tree *Tree) AddEdge(u, v, w int) { tree.Tree[u] = append(tree.Tree[u], [2]int{v, w}) tree.Tree[v] = append(tree.Tree[v], [2]int{u, w}) tree.Edges = append(tree.Edges, [3]int{u, v, w}) } // 添加有向边 u->v, 边权为w. func (tree *Tree) AddDirectedEdge(u, v, w int) { tree.Tree[u] = append(tree.Tree[u], [2]int{v, w}) tree.Edges = append(tree.Edges, [3]int{u, v, w}) } // root:0-based // 当root设为-1时,会从0开始遍历未访问过的连通分量 func (tree *Tree) Build(root int) { if root != -1 { tree.build(root, -1, 0, 0) tree.markTop(root, root) } else { for i := 0; i < len(tree.Tree); i++ { if tree.Parent[i] == -1 { tree.build(i, -1, 0, 0) tree.markTop(i, i) } } } } // 返回 root 的欧拉序区间, 左闭右开, 0-indexed. func (tree *Tree) Id(root int) (int, int) { return tree.LID[root], tree.RID[root] } // 返回边 u-v 对应的 欧拉序起点编号, 0-indexed. func (tree *Tree) Eid(u, v int) int { if tree.LID[u] > tree.LID[v] { return tree.LID[u] } return tree.LID[v] } // 较深的那个点作为边的编号. func (tree *Tree) EidtoV(eid int) int { e := tree.Edges[eid] u, v := e[0], e[1] if tree.Parent[u] == v { return u } return v } func (tree *Tree) LCA(u, v int) int { for { if tree.LID[u] > tree.LID[v] { u, v = v, u } if tree.top[u] == tree.top[v] { return u } v = tree.Parent[tree.top[v]] } } func (tree *Tree) Dist(u, v int, weighted bool) int { if weighted { return tree.DepthWeighted[u] + tree.DepthWeighted[v] - 2*tree.DepthWeighted[tree.LCA(u, v)] } return tree.Depth[u] + tree.Depth[v] - 2*tree.Depth[tree.LCA(u, v)] } // k: 0-based // 如果不存在第k个祖先,返回-1 func (tree *Tree) KthAncestor(root, k int) int { if k > tree.Depth[root] { return -1 } for { u := tree.top[root] if tree.LID[root]-k >= tree.LID[u] { return tree.idToNode[tree.LID[root]-k] } k -= tree.LID[root] - tree.LID[u] + 1 root = tree.Parent[u] } } // 从 from 节点跳向 to 节点,跳过 step 个节点(0-indexed) // 返回跳到的节点,如果不存在这样的节点,返回-1 func (tree *Tree) Jump(from, to, step int) int { if step == 1 { if from == to { return -1 } if tree.IsInSubtree(to, from) { return tree.KthAncestor(to, tree.Depth[to]-tree.Depth[from]-1) } return tree.Parent[from] } c := tree.LCA(from, to) dac := tree.Depth[from] - tree.Depth[c] dbc := tree.Depth[to] - tree.Depth[c] if step > dac+dbc { return -1 } if step <= dac { return tree.KthAncestor(from, step) } return tree.KthAncestor(to, dac+dbc-step) } func (tree *Tree) CollectChild(root int) []int { res := []int{} for _, e := range tree.Tree[root] { next := e[0] if next != tree.Parent[root] { res = append(res, next) } } return res } // 返回沿着`路径顺序`的 [起点,终点] 的 欧拉序 `左闭右闭` 数组. // !eg:[[2 0] [4 4]] 沿着路径顺序但不一定沿着欧拉序. func (tree *Tree) GetPathDecomposition(u, v int, vertex bool) [][2]int { up, down := [][2]int{}, [][2]int{} for { if tree.top[u] == tree.top[v] { break } if tree.LID[u] < tree.LID[v] { down = append(down, [2]int{tree.LID[tree.top[v]], tree.LID[v]}) v = tree.Parent[tree.top[v]] } else { up = append(up, [2]int{tree.LID[u], tree.LID[tree.top[u]]}) u = tree.Parent[tree.top[u]] } } edgeInt := 1 if vertex { edgeInt = 0 } if tree.LID[u] < tree.LID[v] { down = append(down, [2]int{tree.LID[u] + edgeInt, tree.LID[v]}) } else if tree.LID[v]+edgeInt <= tree.LID[u] { up = append(up, [2]int{tree.LID[u], tree.LID[v] + edgeInt}) } for i := 0; i < len(down)/2; i++ { down[i], down[len(down)-1-i] = down[len(down)-1-i], down[i] } return append(up, down...) } func (tree *Tree) GetPath(u, v int) []int { res := []int{} composition := tree.GetPathDecomposition(u, v, true) for _, e := range composition { a, b := e[0], e[1] if a <= b { for i := a; i <= b; i++ { res = append(res, tree.idToNode[i]) } } else { for i := a; i >= b; i-- { res = append(res, tree.idToNode[i]) } } } return res } func (tree *Tree) SubtreeSize(u int) int { return tree.RID[u] - tree.LID[u] } // child 是否在 root 的子树中 (child和root不能相等) func (tree *Tree) IsInSubtree(child, root int) bool { return tree.LID[root] <= tree.LID[child] && tree.LID[child] < tree.RID[root] } func (tree *Tree) ELID(u int) int { return 2*tree.LID[u] - tree.Depth[u] } func (tree *Tree) ERID(u int) int { return 2*tree.RID[u] - tree.Depth[u] - 1 } func (tree *Tree) build(cur, pre, dep, dist int) int { subSize, heavySize, heavySon := 1, 0, -1 for _, e := range tree.Tree[cur] { next, weight := e[0], e[1] if next != pre { nextSize := tree.build(next, cur, dep+1, dist+weight) subSize += nextSize if nextSize > heavySize { heavySize, heavySon = nextSize, next } } } tree.Depth[cur] = dep tree.DepthWeighted[cur] = dist tree.heavySon[cur] = heavySon tree.Parent[cur] = pre return subSize } func (tree *Tree) markTop(cur, top int) { tree.top[cur] = top tree.LID[cur] = tree.timer tree.idToNode[tree.timer] = cur tree.timer++ if tree.heavySon[cur] != -1 { tree.markTop(tree.heavySon[cur], top) for _, e := range tree.Tree[cur] { next := e[0] if next != tree.heavySon[cur] && next != tree.Parent[cur] { tree.markTop(next, next) } } } tree.RID[cur] = tree.timer } type _LST struct { n int size int log int data []E lazy []Id e func() E id func() Id op func(E, E) E mapping func(Id, E) E composition func(Id, Id) Id dataUint E lazyUint Id } func _NewLST( leaves []E, e func() E, id func() Id, op func(E, E) E, mapping func(Id, E) E, composition func(Id, Id) Id, ) *_LST { tree := &_LST{ e: e, id: id, op: op, mapping: mapping, composition: composition, dataUint: e(), lazyUint: id(), } n := len(leaves) tree.n = n tree.log = int(bits.Len(uint(n - 1))) tree.size = 1 << tree.log tree.data = make([]E, tree.size<<1) tree.lazy = make([]Id, tree.size) for i := range tree.data { tree.data[i] = tree.dataUint } for i := range tree.lazy { tree.lazy[i] = tree.lazyUint } for i := 0; i < n; i++ { tree.data[tree.size+i] = leaves[i] } for i := tree.size - 1; i >= 1; i-- { tree.pushUp(i) } return tree } // 查询切片[left:right]的值 // 0<=left<=right<=len(tree.data) func (tree *_LST) Query(left, right int) E { if left < 0 { left = 0 } if right > tree.n { right = tree.n } if left >= right { return tree.dataUint } left += tree.size right += tree.size for i := tree.log; i >= 1; i-- { if ((left >> i) << i) != left { tree.pushDown(left >> i) } if ((right >> i) << i) != right { tree.pushDown((right - 1) >> i) } } sml, smr := tree.dataUint, tree.dataUint for left < right { if left&1 != 0 { sml = tree.op(sml, tree.data[left]) left++ } if right&1 != 0 { right-- smr = tree.op(tree.data[right], smr) } left >>= 1 right >>= 1 } return tree.op(sml, smr) } func (tree *_LST) QueryAll() E { return tree.data[1] } // 更新切片[left:right]的值 // 0<=left<=right<=len(tree.data) func (tree *_LST) Update(left, right int, f Id) { if left < 0 { left = 0 } if right > tree.n { right = tree.n } if left >= right { return } left += tree.size right += tree.size for i := tree.log; i >= 1; i-- { if ((left >> i) << i) != left { tree.pushDown(left >> i) } if ((right >> i) << i) != right { tree.pushDown((right - 1) >> i) } } l2, r2 := left, right for left < right { if left&1 != 0 { tree.propagate(left, f) left++ } if right&1 != 0 { right-- tree.propagate(right, f) } left >>= 1 right >>= 1 } left = l2 right = r2 for i := 1; i <= tree.log; i++ { if ((left >> i) << i) != left { tree.pushUp(left >> i) } if ((right >> i) << i) != right { tree.pushUp((right - 1) >> i) } } } // 二分查询最小的 left 使得切片 [left:right] 内的值满足 predicate func (tree *_LST) MinLeft(right int, predicate func(data E) bool) int { if right == 0 { return 0 } right += tree.size for i := tree.log; i >= 1; i-- { tree.pushDown((right - 1) >> i) } res := tree.dataUint for { right-- for right > 1 && right&1 != 0 { right >>= 1 } if !predicate(tree.op(tree.data[right], res)) { for right < tree.size { tree.pushDown(right) right = right<<1 | 1 if predicate(tree.op(tree.data[right], res)) { res = tree.op(tree.data[right], res) right-- } } return right + 1 - tree.size } res = tree.op(tree.data[right], res) if (right & -right) == right { break } } return 0 } // 二分查询最大的 right 使得切片 [left:right] 内的值满足 predicate func (tree *_LST) MaxRight(left int, predicate func(data E) bool) int { if left == tree.n { return tree.n } left += tree.size for i := tree.log; i >= 1; i-- { tree.pushDown(left >> i) } res := tree.dataUint for { for left&1 == 0 { left >>= 1 } if !predicate(tree.op(res, tree.data[left])) { for left < tree.size { tree.pushDown(left) left <<= 1 if predicate(tree.op(res, tree.data[left])) { res = tree.op(res, tree.data[left]) left++ } } return left - tree.size } res = tree.op(res, tree.data[left]) left++ if (left & -left) == left { break } } return tree.n } // 单点查询(不需要 pushUp/op 操作时使用) func (tree *_LST) Get(index int) E { index += tree.size for i := tree.log; i >= 1; i-- { tree.pushDown(index >> i) } return tree.data[index] } // 单点赋值 func (tree *_LST) Set(index int, e E) { index += tree.size for i := tree.log; i >= 1; i-- { tree.pushDown(index >> i) } tree.data[index] = e for i := 1; i <= tree.log; i++ { tree.pushUp(index >> i) } } func (tree *_LST) pushUp(root int) { tree.data[root] = tree.op(tree.data[root<<1], tree.data[root<<1|1]) } func (tree *_LST) pushDown(root int) { if tree.lazy[root] != tree.lazyUint { tree.propagate(root<<1, tree.lazy[root]) tree.propagate(root<<1|1, tree.lazy[root]) tree.lazy[root] = tree.lazyUint } } func (tree *_LST) propagate(root int, f Id) { tree.data[root] = tree.mapping(f, tree.data[root]) // !叶子结点不需要更新lazy if root < tree.size { tree.lazy[root] = tree.composition(f, tree.lazy[root]) } } func min(a, b int) int { if a < b { return a } return b } func max(a, b int) int { if a > b { return a } return b }