【SPLAY】 [HNOI2002] 營業額統計 模板

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模板

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <string>
#include <iostream>
#include <algorithm>
using namespace std;
#include <queue>
#include <stack>
#include <vector>
#include <list>
#include <deque>
#include <set>
#pragma comment(linker, "/STACK:1024000000,1024000000")
#include <map>
typedef long long LL;
const int INF = 1<<29;
const LL mod = 1e9+7;
const int MAXN = 100050;
struct SPLAY
{
    int pre[MAXN],key[MAXN],ch[MAXN][2],root,tol;
    void init()
    {
        root=0,tol=0;
    }
    void NewNode(int &r,int father,int k)
    {
        r= ++tol;
        pre[r]=father;
        key[r]=k;
        ch[r][0]=ch[r][1]=0;
    }
    void Rotate(int x,int kind)//0爲左旋，1爲右旋
    {
        int y=pre[x];
        ch[y][!kind]=ch[x][kind];
        pre[ch[x][kind]]=y;
        if(pre[y])
            ch[pre[y]][ch[pre[y]][1]==y]=x;
        pre[x]=pre[y];
        ch[x][kind]=y;
        pre[y]=x;
    }
    //Splay調整，將根爲r的子樹調整爲goal
    void Splay(int r,int goal)
    {
        while(pre[r]!=goal)
        {
            if(pre[pre[r]]==goal)
                Rotate(r,ch[pre[r]][0]==r);
            else
            {
                int y=pre[r];
                int kind=ch[pre[y]][0]==y;
                if(ch[y][kind]==r)
                {
                    Rotate(r,!kind);
                    Rotate(r,kind);
                }
                else
                {
                    Rotate(y,kind);
                    Rotate(r,kind);
                }
            }
        }
        if(goal==0) root=r;
    }
    int Insert(int k)
    {
        int r=root;
        while(ch[r][key[r]<k])
        {
            if(key[r]==k)//key不重複
            {
                Splay(r,0);
                return 0;
            }
            r=ch[r][key[r]<k];
        }
        NewNode(ch[r][k>key[r]],r,k);
        Splay(ch[r][k>key[r]],0);
        return 1;
    }
    int get_pre(int x)
    {
        int tmp=ch[x][0];
        if(tmp==0) return INF;
        while(ch[tmp][1]) tmp=ch[tmp][1];
        return key[x]-key[tmp];
    }
    int get_next(int x)
    {
        int tmp=ch[x][1];
        if(tmp==0) return INF;
        while(ch[tmp][0]) tmp=ch[tmp][0];
        return key[tmp]-key[x];
    }
    
}s;
int main()
{
    int n;
    while(scanf("%d",&n)!=EOF)
    {
        int ans=0,x;
        s.init();
        for(int i=1;i<=n;i++)
        {
            if(scanf("%d",&x)==EOF) x=0;
            if(i==1){
                s.NewNode(s.root,0,x);
                ans=x;
                continue;
            }
            if(s.Insert(x)==0) continue;
            ans+=min(s.get_next(s.root),s.get_pre(s.root));
        }
        cout<<ans<<endl;
    }
    return 0;
}