Do it in c++ . Correct code and output screenshot else downvote you will get.
One has a variety of (n is even) numbers a1,a2,… ,an. He considered a positive number k. From that point onward, he started playing out the accompanying procedure on the cluster: take a record I (1≤i≤n) and lessen the number artificial intelligence by k. After Polycarp played out a few (conceivably zero) number of such activities, it worked out that to some degree half of the numbers in the cluster turned into something similar. Track down the greatest k at which such a circumstance is conceivable, or print −1 if a particularly number can be subjectively enormous. Info :The main line contains one number t (1≤t≤10) — the quantity of experiments. Then, at that point, t experiments follow. Each experiment comprises of two lines. The primary line contains an even whole number n (4≤n≤40) (n is even). The subsequent line contains n numbers a1,a2,… an (−106≤ai≤106). It is ensured that the amount of all n indicated in the given experiments doesn't surpass 100.Yield output: For each experiment yield on a different line a number k (k≥1) — the greatest conceivable number that Polycarp utilized in procedure on the cluster, or −1, if a particularly number can be discretionarily enormous.
