splay HYSBZ1588

n天

n个营业额;

sum(min(abs(wi-前面)));

splay维护一下就可以

 #include<stdio.h>
 #include<algorithm>
 #include<math.h>

 using namespace std;
 #define inf 2000000000
 int sum,time,flag,root;

 struct node
 {
     int fa,l,r,w;
 }tree[];
 void rightrotate(int x) //右旋
 {
     int y=tree[x].fa;
     int z=tree[y].fa;
     tree[y].l=tree[x].r;
     if(tree[x].r!=-)
         tree[tree[x].r].fa=y;
     tree[x].fa=z;
     if(z!=-)
     {
         if(tree[z].l==y)
             tree[z].l=x;
         else
             tree[z].r=x;
     }
     tree[x].r=y;
     tree[y].fa=x;
 }
 void leftrotate(int x)//左旋
 {
     int y=tree[x].fa;
     int z=tree[y].fa;
     tree[y].r=tree[x].l;
     if(tree[x].l!=-)
         tree[tree[x].l].fa=y;
     tree[x].fa=z;
     if(z!=-)
     {
         if(tree[z].l==y)
             tree[z].l=x;
         else
             tree[z].r=x;
     }
     tree[x].l=y;
     tree[y].fa=x;
 }
 void splay(int x)
 {
     while(tree[x].fa!=-)
     {
          int y=tree[x].fa;
          int z=tree[y].fa;
          if(z==-)                  //6种旋转情况
          {
              if(tree[y].l==x)
                 rightrotate(x);
              else
                 leftrotate(x);
          }
          else
          {
              if(tree[z].l==y&&tree[y].l==x)
              {
                  rightrotate(y);
                  rightrotate(x);
              }
              else if(tree[z].l==y&&tree[y].r==x)
              {
                  leftrotate(x);
                  rightrotate(x);
              }
              else if(tree[z].r==y&&tree[y].r==x)
              {
                  leftrotate(y);
                  leftrotate(x);
              }
              else
              {
                  rightrotate(x);
                  leftrotate(x);
              }
          }
     }
     root=x;
 }
 void BST_insert(int w,int x)  //插入  就和二叉排序树一样
 {
     if(w==tree[x].w)
     {
         flag=false;
         splay(x);
         return ;
     }
     else if(w<tree[x].w)
     {
         if(tree[x].l==-)
         {
             tree[x].l=time;
             tree[time].fa=x;
             tree[time].l=tree[time].r=-;
             tree[time].w=w;
         }
         else
             BST_insert(w,tree[x].l);
     }
     else
     {
         if(tree[x].r==-)
         {
             tree[x].r=time;
             tree[time].fa=x;
             tree[time].l=tree[time].r=-;
             tree[time].w=w;
         }
         else
             BST_insert(w,tree[x].r);
     }
 }
 int f_pr(int x)  //前面最大
 {
     int y=tree[x].l;
     if(y==-)
         return y;
     while(tree[y].r!=-)
         y=tree[y].r;
     return y;
 }
 int f_ne(int x) //后面最小
 {
     int y=tree[x].r;
     if(y==-)
         return y;
     while(tree[y].l!=-)
         y=tree[y].l;
     return y;
 }
 void Insert(int w)
 {
     flag=true;
     time++;
     BST_insert(w,root);
     if(flag==false)
         return ;
     splay(time);
     int q=f_pr(time);
     int p=f_ne(time);
     int mi=inf;
     if(q!=-)
         mi=min(mi,abs(tree[q].w-w));
     if(p!=-)
         mi=min(mi,abs(tree[p].w-w));
     sum+=mi;
 }
 int main()
 {
     int n;
     while(scanf("%d",&n)!=EOF)
     {
             scanf("%d",&sum);
             time=;
             tree[time].fa=tree[time].l=tree[time].r=-;
             tree[time].w=sum;
             root=time;
             for(int i=;i<n;i++)
             {
                 int a;
                 scanf("%d",&a);
                 Insert(a);
             }
             printf("%d\n",sum);
     }
     return ;
 }