BZOJ 2594 Wc2006 水管局长数据加强版 Link-Cut-Tree

标签：bzoj   bzoj2594   link-cut-tree   kruskal   

题目大意：给定一个无向图，多次删除某条边，多次查询两点之间路径上边权最大值的最小值

Link-Cut-Tree维护动态最小生成树

首先倒着做 将所有被删除的边标记(找边我用的排序+二分) 将没标记的边跑一遍Kruskal 求出最小生成树 然后每次加边和查询正常维护即可

LInk-Cut-Tree一气呵成写完，Kruskal尼玛写挂了…… 居然忘记把并查集连边 这我也是醉了

顺便吐槽一下题干上给的读入优化真尼玛弱……自己随便写一个都可以优化到RANK前十……

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
struct edge{
    int x,y,z;
    bool operator < (const edge &Y) const
    {
        if(x==Y.x)
            return y<Y.y;
        return x<Y.x;
    }
    bool operator < (const pair<int,int> &Y) const
    {
        if(x==Y.first)
            return y<Y.second;
        return x<Y.first;
    }
}edges[1001001];
struct abcd{
    abcd *ls,*rs,*fa;
    int e,max_e;
    bool rev_mark;
    abcd (int x);
    void Push_Up();
    void Push_Down();
    void Reverse();
}*null=new abcd(0),*tree[1100100];
struct query{
    int p,x,y;
}queries[100100];
struct _edge{
    int x,y,z,pos;
    bool operator < (const _edge &Y) const
    {
        return z < Y.z;
    }
    void operator = (const edge &Y)
    {
        x=Y.x;
        y=Y.y;
        z=Y.z;
        pos=(&Y)-edges;
    }
}_edges[1001001];
struct Complex{
    int to,z,next;
}table[200200];
 
int head[100100],tot;
int n,m,q;
bool v[1001001];
int fa[100100];
int stack[100100],top;
 
void Add(int x,int y,int z)
{
    table[++tot].to=y;
    table[tot].z=z;
    table[tot].next=head[x];
    head[x]=tot;
}
int Find(int x)
{
    if(!fa[x]||fa[x]==x)
        return fa[x]=x;
    return fa[x]=Find(fa[x]);
}
inline bool Compare(int x,int y)
{
    return edges[x].z < edges[y].z;
}
abcd :: abcd(int x)
{
    ls=rs=fa=null;
    e=max_e=x;
    rev_mark=0;
}
void abcd :: Push_Up()
{
    max_e=max(ls->max_e,rs->max_e,Compare);
    max_e=max(max_e,e,Compare);
}
void abcd :: Push_Down()
{
    if(fa->ls==this||fa->rs==this)
        fa->Push_Down();
    if(rev_mark)
    {
        ls->Reverse();
        rs->Reverse();
        rev_mark=0;
    }
}
void abcd :: Reverse()
{
    swap(ls,rs);
    rev_mark^=1;
}
void Zig(abcd *x)
{
    abcd *y=x->fa;
    y->ls=x->rs;
    x->rs->fa=y;
    x->rs=y;
    x->fa=y->fa;
    if(y==y->fa->ls)
        y->fa->ls=x;
    else if(y==y->fa->rs)
        y->fa->rs=x;
    y->fa=x;
    y->Push_Up();
}
void Zag(abcd *x)
{
    abcd *y=x->fa;
    y->rs=x->ls;
    x->ls->fa=y;
    x->ls=y;
    x->fa=y->fa;
    if(y==y->fa->ls)
        y->fa->ls=x;
    else if(y==y->fa->rs)
        y->fa->rs=x;
    y->fa=x;
    y->Push_Up();
}
void Splay(abcd *x)
{
    x->Push_Down();
    while(x->fa->ls==x||x->fa->rs==x)
    {
        abcd *y=x->fa,*z=y->fa;
        if(x==y->ls)
        {
            if(y==z->ls)
                Zig(y);
            Zig(x);
        }
        else
        {
            if(y==z->rs)
                Zag(y);
            Zag(x);
        }
    }
    x->Push_Up();
}
inline void Access(abcd *x)
{
    abcd *y=null;
    while(x!=null)
    {
        Splay(x);
        x->rs=y;
        x->Push_Up();
        y=x;x=x->fa;
    }
}
inline void Move_To_Root(abcd *x)
{
    Access(x);
    Splay(x);
    x->Reverse();
}
inline abcd* Find_Root(abcd *x)
{
    while(x->fa!=null)
        x=x->fa;
    return x;
}
inline void Link(abcd *x,abcd *y)
{
    Move_To_Root(x);
    x->fa=y;
}
inline void Cut(abcd *x,abcd *y)
{
    Move_To_Root(x);
    Access(y);
    Splay(y);
    y->ls=null;
    x->fa=null;
    y->Push_Up();
}
 
inline char Get_Char()
{
    static const int len=1<<15;
    static char buffer[len];
    static char *S,*T;
    if(S==T)
    {
        T=(S=buffer)+fread(buffer,1,len,stdin);
        if(S==T)return EOF;
    }
    return *S++;
}
inline int Get_Int()
{
    char c=Get_Char();
    while(c<'0'||c>'9')
        c=Get_Char();
    int re=0;
    while(c>='0'&&c<='9')
        re=(re<<1)+(re<<3)+(c-'0'),c=Get_Char();
    return re;
}
void Kruskal()
{
    int i,top=0;
    for(i=1;i<=m;i++)
        if(!v[i])
            _edges[++top]=edges[i];
    sort(_edges+1,_edges+top+1);
    for(i=1;i<=top;i++)
    {
        int x=_edges[i].x,y=_edges[i].y;
        if( Find(x)==Find(y) )
            continue;
        fa[Find(x)]=Find(y);
        Add(x,y,_edges[i].pos);
        Add(y,x,_edges[i].pos);
    }
}
void DFS(int x,int from,int from_e)
{
    static bool v[100100];
    int i;
    if(v[x]) return ;
    v[x]=1;tree[x]=new abcd(0);
    if(from)
    {
        tree[n+from_e]=new abcd(from_e);
        tree[n+from_e]->fa=tree[from];
        tree[x]->fa=tree[n+from_e];
    }
    for(i=head[x];i;i=table[i].next)
        DFS(table[i].to,x,table[i].z);
}
inline int Query(abcd *x,abcd *y)
{
    Move_To_Root(x);
    Access(y);
    Splay(y);
    return y->max_e;
}
void Insert(int pos)  
{
    abcd *x=tree[edges[pos].x];
    abcd *y=tree[edges[pos].y];
    if( Find_Root(x)==Find_Root(y) )  
    {  
        int temp=Query(x,y);
        if(edges[temp].z<=edges[pos].z)
            return;  
        Cut(tree[n+temp],tree[edges[temp].x]);  
        Cut(tree[n+temp],tree[edges[temp].y]);
    }  
    tree[n+pos]=new abcd(pos);
    Link(x,tree[n+pos]);
    Link(y,tree[n+pos]);
}
int main()
{
     
    //freopen("2594.in","r",stdin);
    //freopen("2594.out","w",stdout);
     
    int i,x,y,z;
    cin>>n>>m>>q;
    for(i=1;i<=m;i++)
    {
        edges[i].x=Get_Int();
        edges[i].y=Get_Int();
        edges[i].z=Get_Int();
    }
    sort(edges+1,edges+m+1);
    for(i=1;i<=q;i++)
    {
        queries[i].p=Get_Int();
        queries[i].x=Get_Int();
        queries[i].y=Get_Int();
        if(queries[i].p==2)
        {
            int temp=lower_bound(edges+1,edges+m+1,make_pair(queries[i].x,queries[i].y) )-edges;
            queries[i].x=temp;
            v[temp]=1;
        }
    }
    Kruskal();
    for(i=1;i<=n;i++)
        DFS(i,0,0);
    for(i=q;i;i--)
    {
        if(queries[i].p==1)
            stack[++top]=edges[Query(tree[queries[i].x],tree[queries[i].y])].z;
        else
            Insert(queries[i].x);
    }
    while(top)
        printf("%d\n",stack[top--]);
}

BZOJ 2594 Wc2006 水管局长数据加强版 Link-Cut-Tree

标签：bzoj   bzoj2594   link-cut-tree   kruskal   

原文地址：http://blog.csdn.net/popoqqq/article/details/41348549