Bzoj 1588:splay Tree

Just learned the splay tree. Knocked on the code of the Great God, and understood a probable

Very useful data structure, can be used to maintain the sequence

It is recommended to look at SBT first so that you can better understand the "rotation"

#include"Cstdio"#include"Queue"#include"Cmath"#include"Stack"#include"iostream"#include"algorithm"#include"CString"#include"Queue"#include"Map"#include"Vector"#definell Long Long#defineMEMS (A, B) memset (A,b,sizeof (a))using namespacestd;Const intMAXN = 1e5+ -;Const intMaxe =200500;Const intINF =0x3f3f3f;intpre[maxn],val[maxn],ch[maxn][2];///father Knot, value, child node (0 left 1 right)intTot,root;///sum of points, root node///The sequence traversal is the maintained sequencevoidNewNodeint&pos,intFaintW) {POS=++tot; Pre[pos]=FA; Val[pos]=W; ch[pos][0]=ch[pos][1]=0;}voidRotate (intXintKind) {///0 left 1 right    intHasPre[x]; ch[fa][!kind]=Ch[x][kind]; Pre[ch[x][kind]]=FA; if(Pre[fa]) ch[pre[fa]][ch[pre[fa]][1]==fa]=x; PRE[X]=PRE[FA]; Ch[x][kind]=A; PRE[FA]=x;}voidSplay (intRintGoal) {///Rotate the R node below goal.     while(pre[r]!=goal) {        if(Pre[pre[r]]==goal) Rotate (r,ch[pre[r]][0]==R); Else{            intHasPre[r]; intkind=ch[pre[fa]][0]==FA; if(CH[FA][KIND]==R) {///alternating left and rightRotate (r,!kind);            Rotate (R,kind); }            Else{///Consistent DirectionRotate (Fa,kind);            Rotate (R,kind); }        }    }    if(!goal) Root=r;///when goal is not present, R is changed to the root node .}BOOLInsert (intkey) {    intR=Root;  while(ch[r][val[r]<Key]) {        if(Val[r]==key) {///The same value is inserted only onceSplay (R,0); return false; } R=ch[r][val[r]<Key]; } newnode (Ch[r][val[r]<Key],r,key); Splay (Ch[r][val[r]<key],0); return true;}///BST Query complexity log (n)intGet_pre (intx) {///looking for numbers larger than X but closest to X    intt=ch[x][0]; if(!t)returnINF;  while(ch[t][1]) t=ch[t][1]; returnval[x]-val[t];}intGet_next (intx) {///looking for a number smaller than x but closest to X    intt=ch[x][1]; if(!t)returnINF;  while(ch[t][0]) t=ch[t][0]; returnval[t]-val[x];}intMain () {intN; //freopen ("In.txt", "R", stdin);     while(~SCANF ("%d",&N)) {Root=tot=0; intans=0;  for(intI=1; i<=n;i++){            intx; if(SCANF ("%d", &x) ==eof) x=0; if(i==1) {ans+=x; NewNode (Root,0, x); Continue; }            if(! Insert (x))Continue; Ans+=min (Get_pre (root), get_next (root)); } cout<<ans<<Endl; }    return 0;}

Bzoj 1588:splay Tree