bzoj 1588 bst

/**************************************************************
    Problem: 1588
    User: BLADEVIL
    Language: C++
    Result: Accepted
    Time:180 ms
    Memory:1468 kb
****************************************************************/
 
//By BLADEVIL
#include <cstdio>
#include <set>
#define inf 1<<30
 
using namespace std;
 
int n,ans;
 
int main()
{
    int x;
    set<int>bt;
    bt.insert(inf); bt.insert(-inf);
    scanf("%d",&n);
    for (int i=1;i<=n;i++)
    {
        //printf(" %d\n",ans);
        if (scanf("%d",&x)==EOF) x=0;
        if (i==1) ans=x,bt.insert(x); else
        {
            int a,b;
            a=*bt.upper_bound(x); b=*(--bt.upper_bound(x));
            ans+=(a-x<x-b)?a-x:x-b;
            bt.insert(x);
        }
    }
    printf("%d\n",ans);
    return 0;
}