Cod sursă (job #112459)

#include <stdio.h>

FILE *fin ,*fout;
int a[100001];
int main()
{
    int n ,i ,t=0;
    fin = fopen("lanterna.in" ,"r");
    fout = fopen("lanterna.out" ,"w");
    fscanf(fin ,"%d" ,&n);
    for(i=1;i<=n;i++)
    {
        fscanf(fin ,"%d" ,&a[i]);
    }
    while(n-2>=2)
    {
        if(a[1]+2*a[2]+a[n] >= a[1]+a[n]+a[n-1]) t+=a[1]+2*a[2]+a[n];
        else t+=a[1]+a[n]+a[n-1];
        n-=2;
    }
    if(n==3)
    {
        t+=a[1]+a[2]+a[3];
    }
    if(n==2)
    {
        t+=a[2];
    }
    fprintf(fout ,"%d" , t);
    return 0;
}