bzoj 1588 营业额统计 splay

http://www.lydsy.com/JudgeOnline/problem.php?id=1588

#include<cstdio>
#include<cstdlib>
const int mod =1000000;
const int inf  = ~0u>>2;
#define KT (ch[ ch[rt][1] ][0])
const int maxn = 200010;
int ans;
struct SplayTree {
    int sz[maxn];
    int ch[maxn][2];
    int pre[maxn];
    int rt,top;
    inline void up(int x){
        sz[x]  = cnt[x]  + sz[ ch[x][0] ] + sz[ ch[x][1] ];
    }
    inline void Rotate(int x,int f){
        int y=pre[x];
        ch[y][!f] = ch[x][f];
        pre[ ch[x][f] ] = y;
        pre[x] = pre[y];
        if(pre[x]) ch[ pre[y] ][ ch[pre[y]][1] == y ] =x;
        ch[x][f] = y;
        pre[y] = x;
        up(y);
    }
    inline void Splay(int x,int goal){//将x旋转到goal的下面
        while(pre[x] != goal){
            if(pre[pre[x]] == goal) Rotate(x , ch[pre[x]][0] == x);
            else   {
                int y=pre[x],z=pre[y];
                int f = (ch[z][0]==y);
                if(ch[y][f] == x) Rotate(x,!f),Rotate(x,f);
                else Rotate(y,f),Rotate(x,f);
            }
        }
        up(x);
        if(goal==0) rt=x;
    }
    inline void RTO(int k,int goal){//将第k位数旋转到goal的下面
        int x=rt;
        while(sz[ ch[x][0] ] != k-1) {
            if(k < sz[ ch[x][0] ]+1) x=ch[x][0];
            else {
                k-=(sz[ ch[x][0] ]+1);
                x = ch[x][1];
            }
        }
        Splay(x,goal);
    }
    inline void vist(int x){
        if(x){
            printf("结点%2d : 左儿子  %2d   右儿子  %2d   %2d sz=%d\n",x,ch[x][0],ch[x][1],val[x],sz[x]);
            vist(ch[x][0]);
            vist(ch[x][1]);
        }
    }
    inline void Newnode(int &x,int c){
        x=++top;
        ch[x][0] = ch[x][1] = pre[x] = 0;
        sz[x]=1; cnt[x]=1;
        val[x] = c;
    }
    inline void init(){
        ans=0;
        ch[0][0]=ch[0][1]=pre[0]=sz[0]=0;
        rt=top=0; cnt[0]=0;
        Newnode(rt,-inf);
        Newnode(ch[rt][1],inf);
        pre[top]=rt;
        sz[rt]=2;
    }
    inline void Insert(int &x,int key,int f){
        if(!x) {
            Newnode(x,key);
            pre[x]=f;
            Splay(x,0);//效率的保证
            return ;
        }
        if(key==val[x]){
            cnt[x]++;
            sz[x]++;
			Splay(x,0);//不加会超时，囧啊
            return ;
        }else if(key<val[x]) {
            Insert(ch[x][0],key,x);
        } else {
            Insert(ch[x][1],key,x);
        }
        up(x);
    }
    void findpre(int x,int key,int &ans){
        if(!x)  return ;
        if(val[x] <= key){
            ans=val[x];
            findpre(ch[x][1],key,ans);
        } else
            findpre(ch[x][0],key,ans);
    }
    void findsucc(int x,int key,int &ans){
        if(!x) return ;
        if(val[x]>=key) {
            ans=val[x];
            findsucc(ch[x][0],key,ans);
        } else
            findsucc(ch[x][1],key,ans);
    }
    void solve() {
		int num;
		num=0;
        scanf("%d",&num);
		int x,y;
		findpre(rt,num,x);
		findsucc(rt,num,y);
		if(abs(x-num) <= abs(y-num)){
			if(x!=-inf) ans+=abs(x-num);
		}else {
			if(y!=inf) ans+=abs(y-num);
		}
		Insert(rt,num,0);
    }
    int cnt[maxn];
    int val[maxn];
  
}spt;
int main()
{
    int n;
    scanf("%d",&n);
    spt.init();
	ans=0;
	scanf("%d",&ans);
	spt.Insert(spt.rt,ans,0);
	n--;
    while(n--) {
		spt.solve();
	}
	printf("%d\n",ans);
    return 0;
}