对于第 $i$ 天的询问
前 $i - c - 1$ 天都会影响答案
主席树维护
#include <iostream> #include <cstdio> #include <algorithm> #include <cmath> #include <cstring> #include <string> using namespace std; #define int long long #define LL long long #define gc getchar() inline int read() {int x = 0; char c = gc; while(c < '0' || c > '9') c = gc; while(c >= '0' && c <= '9') x = x * 10 + c - '0', c = gc; return x;} inline LL read_LL() {LL x = 0; char c = gc; while(c < '0' || c > '9') c = gc; while(c >= '0' && c <= '9') x = x * 10 + c - '0', c = gc; return x;} #undef gc const int N = 2e5 + 10; int Root[N], Lson[N * 25], Rson[N * 25], W[N * 25]; struct Node {int v, nxt;} G[N]; int head[N], cnt; int n, q, Rt; int fa[N], deep[N], size[N], topp[N], son[N], tree[N], treejs; inline void Link(int u, int v) {G[++ cnt].v = v; G[cnt].nxt = head[u]; head[u] = cnt;} void Dfs_1(int u, int f_, int depth) { fa[u] = f_, deep[u] = depth, size[u] = 1; for(int i = head[u]; ~ i; i = G[i].nxt) { int v = G[i].v; if(v == f_) continue; Dfs_1(v, u, depth + 1); size[u] += size[v]; if(size[v] > size[son[u]]) son[u] = v; } } void Dfs_2(int u, int tp) { topp[u] = tp, tree[u] = ++ treejs; if(!son[u]) return ; Dfs_2(son[u], tp); for(int i = head[u]; ~ i; i = G[i].nxt) { int v = G[i].v; if(v != fa[u] && v != son[u]) Dfs_2(v, v); } } inline int Lca(int x, int y) { int tpx = topp[x], tpy = topp[y]; while(tpx != tpy) { if(deep[tpx] < deep[tpy]) swap(x, y), swap(tpx, tpy); x = fa[tpx], tpx = topp[x]; } return deep[x] < deep[y] ? x : y; } int Hjt; void Fill(int x, int y) { Lson[x] = Lson[y], Rson[x] = Rson[y], W[x] = W[y]; } #define lson jd << 1 #define rson jd << 1 | 1 void Sec_G(int &rt, int l, int r, int x) { Fill(++ Hjt, rt); rt = Hjt; W[rt] ++; if(l == r) return ; int mid = (l + r) >> 1; if(x <= mid) Sec_G(Lson[rt], l, mid, x); else Sec_G(Rson[rt], mid + 1, r, x); } int Ans; void Sec_A(int rt, int l, int r, int x, int y) { if(!rt) return ; if(x <= l && r <= y) { Ans += W[rt]; return ; } int mid = (l + r) >> 1; if(x <= mid) Sec_A(Lson[rt], l, mid, x, y); if(y > mid ) Sec_A(Rson[rt], mid + 1, r, x, y); } inline int Sec_A_imp(int rt, int x, int y) { if(rt <= 0) return 0; int ret = 0, tpx = topp[x], tpy = topp[y]; while(tpx != tpy) { if(deep[tpx] < deep[tpy]) swap(x, y), swap(tpx, tpy); Ans = 0; Sec_A(Root[rt], 1, n, tree[tpx], tree[x]); ret += Ans; x = fa[tpx], tpx = topp[x]; } if(deep[x] < deep[y]) swap(x, y); Ans = 0; Sec_A(Root[rt], 1, n, tree[y], tree[x]); ret += Ans; return ret; } main() { n = read(); for(int i = 1; i <= n; i ++) head[i] = -1; for(int i = 1; i <= n; i ++) { int v = read(); if(!v) Rt = i; else Link(v, i); } Dfs_1(Rt, 0, 1); Dfs_2(Rt, Rt); q = read(); for(int i = 1; i <= q; i ++) { int opt = read(); Root[i] = Root[i - 1]; if(opt == 1) { int x = read(), y = read(), C = read(); int a = deep[x] + deep[y] - 2 * deep[Lca(x, y)] + 1; int b = Sec_A_imp(i - C - 1, x, y); cout << a << " " << b << " "; } else { int x = read(); Sec_G(Root[i], 1, n, tree[x]); } } return 0; }