动态树模板题。。。涉及到的就是cut,link和findroot
#include <iostream> #include <queue> #include <stack> #include <map> #include <set> #include <bitset> #include <cstdio> #include <algorithm> #include <cstring> #include <climits> #include <cstdlib> #include <cmath> #include <time.h> #define maxn 2000005 #define maxm 2000005 #define eps 1e-10 #define mod 1000000007 #define INF 0x3f3f3f3f #define PI (acos(-1.0)) #define lowbit(x) (x&(-x)) #define mp make_pair #define ls o<<1 #define rs o<<1 | 1 #define lson o<<1, L, mid #define rson o<<1 | 1, mid+1, R #define pii pair<int, int> //#pragma comment(linker, "/STACK:16777216") typedef long long LL; typedef unsigned long long ULL; //typedef int LL; using namespace std; LL qpow(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base;base=base*base;b/=2;}return res;} LL powmod(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base%mod;base=base*base%mod;b/=2;}return res;} // head struct node *null; struct node { int rev; node *ch[2], *fa; inline bool d() { return fa->ch[1] == this; } inline bool isroot() { return fa == null || fa->ch[0] != this && fa->ch[1] != this; } inline void setc(node *p, int d) { ch[d] = p; p->fa = this; } void rot() { node *f = fa, *ff = fa->fa; int c = d(), cc = fa->d(); f->setc(ch[!c], c); this->setc(f, !c); if(ff->ch[cc] == f) ff->setc(this, cc); else this->fa = ff; } void flip() { if(this == null) return; swap(ch[0], ch[1]); rev ^= 1; } void pushdown() { if(rev) { ch[0]->flip(); ch[1]->flip(); rev = 0; } } void go() { if(!isroot()) fa->go(); pushdown(); } node* splay() { go(); while(!isroot()) { if(!fa->isroot()) d() == fa->d() ? fa->rot() : rot(); rot(); } return this; } node* access() { for(node *p = this, *q = null; p != null; q = p, p = p->fa) p->splay()->setc(q, 1); return splay(); } void makeroot() { access()->flip(); } node* findroot() { node *p; for(p = access(); p->ch[0] != null; p = p->ch[0]); return p; } void link(node *p) { makeroot(); fa = p; } void cut(node *p) { p->makeroot(); this->access(); p->fa = ch[0] = null; } }; node *Node[maxn]; node pool[maxn]; node *tail; char s[1005]; int n, m; void init() { tail = pool; null = tail++; null->ch[0]= null->ch[1] = null->fa = null; for(int i = 1; i <= n; i++) { tail->ch[0] = tail->ch[1] = tail->fa = null; tail->rev = 0; Node[i] = tail++; } } void work() { int a, b; init(); while(m--) { scanf("%s%d%d", s, &a, &b); if(s[0] == 'C') Node[a]->link(Node[b]); if(s[0] == 'D') Node[a]->cut(Node[b]); if(s[0] == 'Q') { if(Node[a]->findroot() == Node[b]->findroot()) printf("Yes\n"); else printf("No\n"); } } } int main(void) { while(scanf("%d%d", &n, &m)!=EOF) work(); return 0; }