2016-05-30 11:04:51
学习了link-cut-tree
二中神犇封禹的讲义感觉讲的超级清晰易懂啊（没有的可以q窝
算是模板吧
#include<bits/stdc++.h> #define N 10005 #define inf 1000000000 #define ll long long using namespace std; int read(){ int x=0,f=1;char ch=getchar(); while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();} while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();} return x*f; } namespace LCT{ int ch[N][2],fa[N];bool rev[N]; inline bool isroot(int x){ if(ch[fa[x]][0]!=x&&ch[fa[x]][1]!=x)return 1;return 0; } inline void pushdown(int x){ if(rev[x]){ rev[ch[x][0]]^=1;rev[ch[x][1]]^=1;rev[x]=0; swap(ch[x][0],ch[x][1]); } } void Pushdown(int x){ if(!isroot(x))Pushdown(fa[x]);//splay中是否是根 pushdown(x); } void rotate(int x){ int y=fa[x],k=ch[y][1]==x; if(!isroot(y))ch[fa[y]][ch[fa[y]][1]==y]=x; fa[x]=fa[y]; fa[y]=x; fa[ch[x][!k]]=y; ch[y][k]=ch[x][!k]; ch[x][!k]=y; } void splay(int x){ Pushdown(x); for(int y=fa[x];!isroot(x);y=fa[x]){ if(!isroot(y)){ if((ch[fa[y]][1]==y)!=(ch[y][1]==x))rotate(x); else rotate(y); }rotate(x); } } inline void access(int x){ int y=0; while(x){ splay(x); ch[x][1]=y; x=fa[y=x]; } } inline void moveroot(int x){ access(x);splay(x);rev[x]^=1; } inline void link(int x,int y){ moveroot(x);fa[x]=y;splay(x); } inline void cut(int x,int y){ moveroot(x);access(y);splay(y);ch[y][0]=fa[x]=0; } inline int find(int x){ access(x);splay(x); while(ch[x][0]){ x=ch[x][0]; pushdown(x); } return x; } } int n,m; char ch[10]; int main(){ n=read();m=read(); while(m--){ scanf("%s",ch); int x=read(),y=read(); if(ch[0]=='C')LCT::link(x,y); else if(ch[0]=='D')LCT::cut(x,y); else if(LCT::find(x)==LCT::find(y))printf("Yes\n");else printf("No\n"); } return 0; }