Why my code is getting WA ??? I have checked all the possible input from uDebug & UVa OJ Board. Still getting WA. Anyone please help me .

Problem : Uva 12032 — The Monkey and the Oiled Bamboo Here is my Code ---

include<bits/stdc++.h>

using namespace std;

map <long long,long long> mp; int main() { // freopen ("myfile.txt","w",stdout);

int tc,kase=1;
scanf("%d",&tc);
while(tc--)
{
    mp.clear();
    long long ara[100001],pa;
    long long n,mx=0,a,diff;
    scanf("%lld",&n);
    scanf("%lld",&ara[0]);
    mx=ara[0];
    mp[mx]++;
    a=mx-1;


    for(long long int i=1; i<n; i++)
    {
        scanf("%lld",&ara[i]);
        diff=ara[i]- ara[i-1];






        mp[diff]++;

        if(diff==a)
            a--;

        else if(diff==mx)
        {




            if(mp[mx]>1)
            {
                mp[mx]=0;
                mx++;
                a=mx-1;
            }

        }


        else if(diff>a)
        {

            if(mx<diff)
                mx = diff;

            else if(diff<mx)
                mx++;

            a=mx-1;
        }



        // cout<<" diff = "<<diff<<" . mx = "<<mx<<" . ability = "<<a<<endl;



    }



    printf("Case %d: %lld\n",kase++,mx);
}
//  fclose(stdout);

}