PAT (Advanced Level) 1008. Elevator (20)

#include<iostream>
#include<cstring>
#include<cmath>
#include<algorithm>
#include<cstdio>
#include<vector>
using namespace std;

const int maxn=100+10;
int n,a[maxn];

int main()
{
    scanf("%d",&n);
    for(int i=1;i<=n;i++) scanf("%d",&a[i]);
    a[0]=0;
    int ans=0;
    for(int i=1;i<=n;i++)
    {
        if(a[i]>a[i-1]) ans=ans+(a[i]-a[i-1])*6,ans=ans+5;
        else if(a[i]<a[i-1]) ans=ans+(a[i-1]-a[i])*4,ans=ans+5;
        else ans=ans+5;
    }
    printf("%d\n",ans);
    return 0;
}