BZOJ 2049 Cave 洞穴勘测 [LCT]

来源：互联网发布：sha1 js 时间编辑：程序博客网时间：2024/05/21 15:00
LCT模板裸题，pushdown要注意，Splay练手。
#include<cstdio>#include<cstring>#include<iostream>#include<algorithm>const int N = 200110;const int INF = 0x3f3f3f3f;using namespace std;inline void read(int &res){    register int flag=1;static char ch;    while((ch=getchar())<'0'||ch>'9')if(ch=='-')flag=-1;res=ch-48;    while((ch=getchar())>='0'&&ch<='9')res=res*10+ch-48;res*=flag;}int n,m,fa[N],c[N][2],st[N];bool rev[N];char cmd[10];inline bool isroot(int x){    return c[fa[x]][0]!=x&&c[fa[x]][1]!=x;}inline void pushdown(int x){    register int l=c[x][0],r=c[x][1];    if(rev[x]){        rev[x]^=1;rev[l]^=1;rev[r]^=1;        swap(c[x][0],c[x][1]);    }}inline void rotate(int x){    register int y=fa[x],z=fa[y],l,r;    if(c[y][0]==x)l=0;    else l=1;r=l^1;    if(!isroot(y)){        if(c[z][0]==y)c[z][0]=x;        else c[z][1]=x;    }    fa[x]=z;fa[y]=x;fa[c[x][r]]=y;    c[y][l]=c[x][r];c[x][r]=y;}inline void splay(int x){    register int top=0;st[++top]=x;    for(register int i=x;!isroot(i);i=fa[i]){        st[++top]=fa[i];    }    for(register int i=top;i;i--)pushdown(st[i]);    while(!isroot(x)){        register int y=fa[x],z=fa[y];        if(!isroot(y)){            if(c[y][0]==x^c[z][0]==y)rotate(x);            else rotate(y);        }        rotate(x);    }}inline void access(int x){    register int t=0;    while(x){        splay(x);        c[x][1]=t;        t=x;x=fa[x];    }}inline void rever(int x){    access(x);splay(x);rev[x]^=1;}inline  void link(int x,int y){    rever(x);fa[x]=y;splay(x);}inline void cut(int x,int y){    rever(x);access(y);splay(y);c[y][0]=fa[x]=0;}inline int find(int x){    access(x);splay(x);    register int y=x;    while(c[y][0])y=c[y][0];    return y;}int main(){    read(n),read(m);    for(register int x,y,i=1;i<=m;i++){        scanf("%s",cmd),read(x),read(y);        if(cmd[0]=='C')link(x,y);        else if(cmd[0]=='D')cut(x,y);        else if(find(x)==find(y))printf("Yes\n");        else printf("No\n");    }    return 0;}
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