【LCT】BZOJ2049(Sdoi2008)[Cave 洞穴勘測]題解

題目概述

有 n 個點， m 個操作，操作有三種：1.連接 x 和 y 。2.斷開 x 和 y 。3.詢問 x 和 y 是否連通。

解題報告

LCT裸題嘍，以前板子太長了，我來放個新板子QAQ。

#include<cstdio>
#include<cctype>
#include<algorithm>
using namespace std;
const int maxn=10000;

int n,te,son[maxn+5][2],fa[maxn+5],flip[maxn+5];

#define Eoln(x) ((x)==10||(x)==13||(x)==EOF)
inline char readc(){
    static char buf[100000],*l=buf,*r=buf;
    if (l==r) r=(l=buf)+fread(buf,1,100000,stdin);
    if (l==r) return EOF;return *l++;
}
inline int readi(int &x){
    int tot=0,f=1;char ch=readc(),lst='+';
    while (!isdigit(ch)) {if (ch==EOF) return EOF;lst=ch;ch=readc();}
    if (lst=='-') f=-f;
    while (isdigit(ch)) tot=(tot<<3)+(tot<<1)+ch-48,ch=readc();
    return x=tot*f,Eoln(ch);
}
inline char getupr() {char ch=readc();while (!isupper(ch)) ch=readc();return ch;}
#define is_ro(p) ((p)!=son[fa[p]][0]&&(p)!=son[fa[p]][1])
#define Son(p) ((p)==son[fa[p]][1])
inline void Rotate(int t){
    int p=fa[t],d=Son(t)^1;son[p][d^1]=son[t][d];son[t][d]=p;
    if (!is_ro(p)) son[fa[p]][Son(p)]=t;
    if (son[p][d^1]) fa[son[p][d^1]]=p;fa[t]=fa[p];fa[p]=t;
}
inline void Addflip(int p) {swap(son[p][0],son[p][1]);flip[p]^=1;}
inline void Pushdown(int p) {if (flip[p]) flip[p]^=1,Addflip(son[p][0]),Addflip(son[p][1]);}
inline void Splay(int p){
    static int top,stk[maxn+5];top=0;stk[++top]=p;
    for (int i=p;!is_ro(i);i=fa[i]) stk[++top]=fa[i];
    while (top) Pushdown(stk[top--]);
    for (int pre=fa[p];!is_ro(p);Rotate(p),pre=fa[p])
        if (!is_ro(pre)) Rotate(Son(p)==Son(pre)?pre:p);
}
inline void Access(int p) {for (int lst=0;p;lst=p,p=fa[p]) Splay(p),son[p][1]=lst;}
inline void Makero(int x) {Access(x);Splay(x);Addflip(x);}
inline void Link(int x,int y) {Makero(x);fa[x]=y;}
inline void Cut(int x,int y) {Makero(x);Access(y);Splay(y);fa[x]=son[y][0]=0;}
inline int getfa(int x) {Access(x);Splay(x);while (son[x][0]) x=son[x][0];return x;}
int main(){
    freopen("program.in","r",stdin);
    freopen("program.out","w",stdout);
    for (readi(n),readi(te);te;te--){
        char td=getupr();int x,y;readi(x);readi(y);
        if (td=='Q') puts(getfa(x)==getfa(y)?"Yes":"No");
        else if (td=='C') Link(x,y); else Cut(x,y);
    }
    return 0;
}