BZOJ 2049 [Sdoi2008]Cave 洞穴勘测

动态树裸题，直接放代码

/**************************************************************    Problem: 2049    User: vermouth    Language: C++    Result: Accepted    Time:2188 ms    Memory:1724 kb****************************************************************/ #include<cstdio>#include<iostream>using namespace std;const int maxn=21000;int n,m,x,y,sz[maxn],fa[maxn],tree[maxn][2],s[maxn];bool rev[maxn];bool isroot(int x){    return tree[fa[x]][0]!=x&&tree[fa[x]][1]!=x;}inline void pushup(int x){    sz[x]=sz[tree[x][0]]+sz[tree[x][1]]+1;}inline void pushdown(int x){    if(rev[x])    {        rev[x]^=1;rev[tree[x][0]]^=1;rev[tree[x][1]]^=1;        swap(tree[x][0],tree[x][1]);    }}void rotate(int x){    int y=fa[x],z=fa[y],l=tree[y][1]==x,r=l^1;    if(!isroot(y)) tree[z][tree[z][1]==y]=x;    fa[x]=z;fa[y]=x;fa[tree[x][r]]=y;    tree[y][l]=tree[x][r];tree[x][r]=y;    pushup(y);pushup(x);}void splay(int x){    int top=0;s[++top]=x;    for(int i=x;!isroot(i);i=fa[i])    {        s[++top]=fa[i];    }    for(int i=top;i;i--) pushdown(s[i]);    while(!isroot(x))    {        int y=fa[x],z=fa[y];        if(!isroot(y))        {            if(tree[y][0]==x^tree[z][0]==y) rotate(y);else rotate(x);        }        rotate(x);    }}void access(int x){    int t=0;    while(x)    {        splay(x);        tree[x][1]=t;        t=x;x=fa[x];    }}void rever(int x){    access(x);splay(x);rev[x]^=1; }void link(int x,int y){    rever(x);fa[x]=y;splay(x); } void cut(int x,int y){    rever(x);access(y);splay(y);tree[y][0]=fa[x]=0;}int find(int x){    access(x);splay(x);    int y=x;    while(tree[y][0]) y=tree[y][0];    return y;}char op[10];int main(){    scanf("%d%d",&n,&m);    for(int i=1;i<=m;i++)    {        scanf("%s",op);        scanf("%d%d",&x,&y);        if(op[0]=='C') link(x,y);        else if(op[0]=='Q')        {            if(find(x)==find(y)) puts("Yes");else puts("No");        }         else if(op[0]=='D') cut(x,y);    }    return 0;}/*200 5Query 123 127Connect 123 127Query 123 127Destroy 127 123Query 123 127*/