BZOJ_2594_[Wc2006]水管局长数据加强版_LCT

#include <stdio.h>
#include <string.h>
#include <algorithm>
using namespace std;
char nc() {
    static char buf[100000],*p1,*p2;
    return p1==p2&&(p2=(p1=buf)+fread(buf,1,100000,stdin),p1==p2)?EOF:*p1++;
}
inline int rd() {
    register int x=0; register char s=nc();
    while(s<‘0‘||s>‘9‘)s=nc();
    while(s>=‘0‘&&s<=‘9‘)x=(x<<3)+(x<<1)+s-‘0‘,s=nc();
    return x;
}
#define N 100050
#define M 1100050
#define ls ch[p][0]
#define rs ch[p][1]
#define get(x) (ch[f[x]][1]==x)
int ch[M][2],f[M],val[M],rev[M],tot,mx[M],n,m,qs,fa[N];
int killx[M],killy[M],ans[M],nxt[M];
int find(int x) {
    return fa[x]==x?x:fa[x]=find(fa[x]);
}
struct A {
    int x,y,v,id,flg;
}e[M],ev[M];
bool cmp1(const A &x,const A &y) {
    if(x.x==y.x) return x.y<y.y;
    return x.x<y.x;
}
bool cmp2(const A &x,const A &y) {
    return x.v<y.v;
}
struct QAQ {
    int opt,x,y,pos;
}q[N];
inline bool isrt(int p) {
    return ch[f[p]][0]!=p&&ch[f[p]][1]!=p;
}
inline void pushup(int p) {
    mx[p]=p;
    if(val[mx[ls]]>val[mx[p]]) mx[p]=mx[ls];
    if(val[mx[rs]]>val[mx[p]]) mx[p]=mx[rs];
}
inline void pushdown(int p) {
    if(rev[p]) {
        swap(ch[ls][0],ch[ls][1]);
        swap(ch[rs][0],ch[rs][1]);
        rev[ls]^=1; rev[rs]^=1; rev[p]=0;
    }
}
void update(int p) {
    if(!isrt(p)) update(f[p]);
    pushdown(p); 
}
void rotate(int x) {
    int y=f[x],z=f[y],k=get(x);
    if(!isrt(y)) ch[z][ch[z][1]==y]=x;
    ch[y][k]=ch[x][!k]; f[ch[y][k]]=y;
    ch[x][!k]=y; f[y]=x; f[x]=z;
    pushup(y); pushup(x);
}
void splay(int x) {
    update(x);
    for(int fa;fa=f[x],!isrt(x);rotate(x))
        if(!isrt(fa))
            rotate(get(fa)==get(x)?fa:x);
}
void access(int p) {
    int t=0;
    while(p) splay(p),rs=t,pushup(p),t=p,p=f[p];
}
void makeroot(int p) {
    access(p); splay(p); swap(ls,rs); rev[p]^=1;
}
void link(int x,int p) {
    makeroot(x); splay(p); f[x]=p;
}
void cut(int x,int p) {
    makeroot(x); access(p); splay(p); ls=f[x]=0;
}
int query(int x,int p) {
    makeroot(x); access(p); splay(p); return mx[p];
}
int search(int x,int y) {
    int l=1,r=m+1;
    while(l<r) {
        int mid=(l+r)>>1;
        if(x>e[mid].x) l=mid+1;
        else r=mid;
    }
    r=nxt[x]+1;
    while(l<r) {
        int mid=(l+r)>>1;
        if(y>e[mid].y) l=mid+1;
        else r=mid;
    }
    return l;
}
int main() {
    n=rd(); m=rd(); qs=rd();
    register int i,x,y,dx,dy,tmp,d;
    for(i=1;i<=m;i++) {
        //e为x升序边便于二分
        e[i].x=rd(),e[i].y=rd(),e[i].v=rd();
        if(e[i].x>e[i].y) swap(e[i].x,e[i].y);
    }
    sort(e+1,e+m+1,cmp1);
    for(i=1;i<=n;i++) fa[i]=i;
    //ev为权值排序
    for(i=1;i<=m;i++) ev[i]=e[i],nxt[e[i].x]=max(nxt[e[i].x],i)/*,printf("e[i].x=%d,nxt[e[i].x]=%d\n",e[i].x,nxt[e[i].x])*/;
    for(i=1;i<=qs;i++) {
        q[i].opt=rd(); q[i].x=rd(); q[i].y=rd();
        if(q[i].opt==1) continue; 
        if(q[i].x>q[i].y) swap(q[i].x,q[i].y);
        q[i].pos=search(q[i].x,q[i].y); 
        //printf("q[i].pos=%d ,q[i].x=%d ,q[i].y=%d\n",q[i].pos,q[i].x,q[i].y);
        e[q[i].pos].flg=ev[q[i].pos].flg=1;
    }
    int tot=n,cnt=0;
    sort(ev+1,ev+m+1,cmp2);
    for(i=1;i<=m;i++) {
        if(!ev[i].flg) {
            int x=ev[i].x,y=ev[i].y;
            int dx=find(x),dy=find(y);
            if(dx!=dy) {
                //printf("x=%d , y=%d\n",x,y);
                tot++; val[tot]=ev[i].v; killx[tot]=x; killy[tot]=y; mx[tot]=tot;
                link(x,tot); link(tot,y); fa[dx]=dy;
            }
        }
    }
    for(i=qs;i;i--) {
        x=q[i].x; y=q[i].y;
        if(q[i].opt==1) {
            makeroot(x); access(y); splay(y);
            ans[++cnt]=val[mx[y]];
        }else {
            int tmp=q[i].pos;
            int dx=find(x),dy=find(y);
            if(dx!=dy) {
                tot++; val[tot]=e[tmp].v; killx[tot]=x; killy[tot]=y; mx[tot]=tot;
                link(x,tot); link(tot,y); fa[dx]=dy;
            }else {
                int d=query(x,y); 
                if(val[d]>e[tmp].v) {
                    tot++; val[tot]=e[tmp].v; killx[tot]=x; killy[tot]=y; mx[tot]=tot;
                    cut(killx[d],d); cut(d,killy[d]); link(x,tot); link(tot,y);
                }
            }
        }
    }
    for(i=cnt;i;i--) {
        printf("%d\n",ans[i]);
    }
}