[UVa] 11850 - Alaska

With this, I finish 300 solves in UVa. :) Took too long.
My stats at the moment:

Submissions: 1701
Problems tried: 322
Problems solved: 300
First submission: 2009-11-17
Last submission: 2011-10-21

And details on the last submission:
Problem number: 11850
Rank of solution: 225
Submission number: 9395891
Date: 2011-10-21
Time: 20:54:39
Runtime: 0.008

Method:
1. Take the input and sort the array.
2. Check if between two consecutive stations the distance is > 200. If so IMPOSSIBLE
3. At last she has to go to the destination and come back to the last station, so check if (1422-[last station])X2 > 200.

#include <stdio.h>
#include <stdlib.h>

int cmp(const void *a, const void *b)
{
    return (*(int*)a - *(int*)b);
}
int miles[4000];
int main()
{
    int n, i, set;
    while (scanf("%d",&n) && n)
    {
        for (i=0 ; i<n ; i++)
            scanf("%d",&miles[i]);
        qsort(miles,n,sizeof(int),cmp);
        set=1;

        for (i=1 ; i<n && set ; i++)
        {
            if (miles[i]-miles[i-1]>200) set=0;
        }
        if (2*(1422-miles[n-1])>200) set=0;
        if (set) printf("POSSIBLE\n");
        else printf("IMPOSSIBLE\n");
    }
    return 0;
}