BZOJ3673 durable array implementations can be persisted and checked (very long) by the persistence of the segment tree

Segment tree only with leaf nodes feel inexplicable waste,,,

It feels good to write (someone who just escaped from a future program)

1#include <cstdio>2 #defineMid ((l+r) >>1)3 intn,m,time,n=0, Ca,x,y;4 introot[500000],ls[4000000],rs[4000000],a[4000000];5 intChangeintXinty)6 {7     intL=1, r=n,now=++n,past=Root[time];8root[++time]=N;9      while(l!=R)Ten         if(X<=mid) rs[now]=rs[past],ls[now]=++n,r=mid,now=ls[now],past=Ls[past]; One         ElseLs[now]=ls[past],rs[now]=++n,l=mid+1, now=rs[now],past=Rs[past]; Aa[now]=y; - } - intQueintx) the { -     intL=1, r=n,now=Root[time]; -      while(l!=R) -         if(X<=mid) r=mid,now=Ls[now]; +         ElseL=mid+1, now=Rs[now]; -     returnA[now]; + } A int Get(intp) at { -      for(intT=que (P); T!=p;t=que (p)) p=T; -     returnp; - } - intMain () - { inscanf"%d%d",&n,&m); -Root[time=0]=1; to      for(intI=1; i<=n;i++) + Change (i,i); -     intstart=Time ; the      for(intI=1; i<=m;i++) *     { $scanf"%d%d",&ca,&x);Panax Notoginseng         if(ca==2) root[++time]=root[x+start]; -         Else thescanf"%d", &y), (ca==1)? Change (Get(y),Get(x)):( root[time+1]=root[time++],printf ("%d\n",Get(x) = =Get(y))); +     } A     return 0; the}

BZOJ3673 durable array implementations can be persisted and checked (very long) by the persistence of the segment tree