Bzoj 4668: The Cold War

Description

On a diagram, connect one edge between two points and ask when the two points first unicom.

Sol

and search set + heuristic merge.

Combined by rank and check set ... I do not know what is combined by rank, anyway, similar to the heuristic merge, when the merger will be small to large satowa, because each growth is a small set multiples of more than twice times, so the number of layers not more than \ (log n\)

And then even when the edge of the record is the number of connections, statistical depth, the final violence to find LCA ...

Code

/************************************************************** problem:4668 User:beiyu language:c++ Result : Accepted time:1256 ms memory:9104 kb****************************************************************/#include &lt ; bits/stdc++.h>using namespace Std; const int N = 5E5+50;    int n,lst;struct uniontable {int f[n],s[n],v[n],d[n];    void init (int n) {for (int i=1;i<=n;i++) f[i]=i,v[i]=0,s[i]=1;            } int find (int x) {if (f[x]^x) {int fa=find (f[x]);            d[x]=d[f[x]]+1;        return FA;    }else return x;        } void Union (int x,int y,int c) {int f1=find (x), F2=find (y);        if (F1==F2) return;        if (S[f1]>s[f2]) F[F2]=F1,V[F2]=C,S[F1]+=S[F2];    else F[F1]=F2,V[F1]=C,S[F2]+=S[F1];        } int Query (int x,int y) {int f1=find (x), F2=find (y), r=0;        if (F1!=F2) return 0; for (; x^y;)            {if (D[x]<d[y]) swap (x, y);        R=max (R,v[x]), x=f[x];    }return R; }}un;    inline int in (int x=0,char Ch=getchar ()) {while (ch> ' 9 ' | | ch< ' 0 ') Ch=getchar (); while (ch>= ' 0 ' && ch<= ' 9 ') x=x*10+ch-' 0 ', Ch=getchar (); return x;    }int Main () {n=in ();    Un.init (n); for (int m=in (), c=0;m--;)        {int opt=in (), U=in () ^lst,v=in () ^lst; if (!opt) un.        Union (U,V,++C); else printf ("%d\n", Lst=un.    Query (u,v)); }return 0;}

Bzoj 4668: The Cold War