[Luogu] 部落冲突--00
Posted
tags:
篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了[Luogu] 部落冲突--00相关的知识,希望对你有一定的参考价值。
https://www.luogu.org/problemnew/show/P3950
思路简单,树剖不用动脑子
#include <bits/stdc++.h> using namespace std; const int N = 3e5 + 10; #define gc getchar() #define lson jd << 1 #define rson jd << 1 | 1 struct Node_1{ int v, nxt; }G[N << 1]; struct Node_2{ int fa, son, deep, topp, siz, tree; }P[N]; struct Node_3{ int l, r, w; }T[N << 2]; int n, Ti, now = 1, head[N], LCAi, u1[N], u2[N], js, LCA, tim, ans; 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 void add(int u, int v){ G[now].v = v; G[now].nxt = head[u]; head[u] = now ++; } void dfs_find_son(int u, int fa, int dep){ P[u].fa = fa; P[u].deep = dep; P[u].siz = 1; for(int i = head[u]; ~ i; i = G[i].nxt){ int v = G[i].v; if(v != fa){ dfs_find_son(v, u, dep + 1); P[u].siz += P[v].siz; if(P[v].siz > P[P[u].son].siz) P[u].son = v; } } } void dfs_to_un(int u, int tp){ P[u].topp = tp; P[u].tree = ++ tim; if(!P[u].son) return ; dfs_to_un(P[u].son, tp); for(int i = head[u]; ~ i; i = G[i].nxt){ int v = G[i].v; if(v != P[u].son && v != P[u].fa) dfs_to_un(v, v); } } void build_tree(int l, int r, int jd){ T[jd].l = l; T[jd].r = r; if(l == r) return ; int mid = (l + r) >> 1; build_tree(l, mid, lson); build_tree(mid + 1, r, rson); } void Poi_G(int l, int r, int jd, int x, int yj){ if(l == r) { T[jd].w += ((r - l + 1) * yj); return ; } int mid = (l + r) >> 1; if(x <= mid) Poi_G(l, mid, lson, x, yj); else Poi_G(mid + 1, r, rson, x, yj); T[jd].w = T[lson].w + T[rson].w; } void Sec_A(int l, int r, int jd, int x, int y){ if(x <= l && r <= y){ ans += T[jd].w; return ; } int mid = (l + r) >> 1; if(x <= mid) Sec_A(l, mid, lson, x, y); if(y > mid) Sec_A(mid + 1, r, rson, x, y); } inline void Sec_A_imp(int x, int y){ int tp1 = P[x].topp, tp2 = P[y].topp; ans = 0; while(tp1 != tp2){ if(P[tp1].deep < P[tp2].deep) swap(x, y), swap(tp1, tp2); Sec_A(1, n, 1, P[tp1].tree, P[x].tree); if(ans != 0){ puts("No"); return ; } x = P[tp1].fa; tp1 = P[x].topp; } /*if(x == y) { puts("Yes"); return ; }*/ if(P[x].deep > P[y].deep) swap(x, y); Sec_A(1, n, 1, P[x].deep + 1, P[y].deep); if(ans) puts("No"); else puts("Yes"); return ; } void debug(){ for(int i = 1; i <= n; i ++) cout << i << ":" << P[i].tree << endl; exit(0); } int main() { freopen("lct.in", "r", stdin); freopen("lct.out", "w", stdout); n = read(); Ti = read(); for(int i = 1; i <= n; i ++) head[i] = -1; for(int i = 1; i < n; i ++) { int u = read(), v = read(); add(u, v); add(v, u); } dfs_find_son(1, 0, 1); dfs_to_un(1, 1); build_tree(1, n, 1); // debug(); while(Ti --){ string s; cin >> s; if(s[0] == ‘U‘){ int x = read(); int point = P[P[u1[x]].deep > P[u2[x]].deep ? u1[x] : u2[x]].tree; Poi_G(1, n, 1, point, -1); } else if(s[0] == ‘C‘){ u1[++ js] = read(), u2[js] = read(); int point = P[P[u1[js]].deep > P[u2[js]].deep ? u1[js] : u2[js]].tree; Poi_G(1, n, 1, point, 1); } else{ int x = read(), y = read(); Sec_A_imp(x, y); } } return 0; }
以上是关于[Luogu] 部落冲突--00的主要内容,如果未能解决你的问题,请参考以下文章