第一次用链表写splay，好不习惯，不会调，于是乎调得要死QAQ
还要orzLSJ神犇，代码实在太精练了
1 #include<bits/stdc++.h> 2 #define inc(i,l,r) for(i=l;i<=r;i++) 3 #define dec(i,l,r) for(i=l;i>=r;i--) 4 #define inf 1e9 5 #define mem(a) memset(a,0,sizeof(a)) 6 using namespace std; 7 int x,s,i,n; 8 struct node *null; 9 struct node{ 10 int v; 11 node *c[2],*f; 12 node(int x,node *fa){ 13 v=x;f=fa;c[0]=c[1]=null; 14 } 15 inline void set(node *ch,int d){ 16 c[d]=ch;ch->f=this; 17 } 18 inline bool d(){ 19 return this==f->c[1]; 20 } 21 }*root; 22 void rot(node *x){ 23 node *y=x->f; 24 int d=!x->d(); 25 y->f->set(x,y->d()); 26 y->set(x->c[d],!d); 27 x->set(y,d); 28 if(x->f==null)root=x; 29 } 30 void splay(node *x,node *goal){ 31 for(node *y=x->f;y!=goal;y=x->f){ 32 if(y->f!=goal) 33 x->d()!=y->d()?rot(x):rot(y); 34 rot(x); 35 } 36 } 37 int insert(int x){ 38 node *r; 39 for(r=root;r->c[r->v<x]!=null;r=r->c[r->v<x]) 40 if(r->v==x)return 1; 41 if(r->v==x)return 1; 42 r=r->c[r->v<x]=new node(x,r); 43 splay(r,null); 44 return 0; 45 } 46 int pre(){ 47 if(root->c[0]==null)return -inf; 48 for(node *r=root->c[0];;r=r->c[1]) 49 if(r->c[1]==null)return r->v; 50 } 51 int next(){ 52 if(root->c[1]==null)return inf; 53 for(node *r=root->c[1];;r=r->c[0]) 54 if(r->c[0]==null)return r->v; 55 } 56 int main(){ 57 null=new node(-inf,NULL); 58 scanf("%d",&n); 59 inc(i,1,n){ 60 scanf("%d",&x); 61 if(i==1){ 62 s=x; 63 root=new node(x,null); 64 }else{ 65 if(insert(x))continue; 66 int a=pre(),b=next(); 67 s+=min(x-a,b-x); 68 } 69 } 70 printf("%d",s); 71 return 0; 72 }