Question

Will the victim get justice if only one person performs all the functions? Give reasons.

Answer 1

Which one person is performing all the functions? Victim? Or the Accused?
What functions are you talking about?
Please be more specific.

Answer 2

Though you have not specified which victim which actions and which performance. But for justice to prevail honesty should be constant. So even one person performs all the functions and the outcome of his decision is given  virtue of fidelity the justice should have prevailed but if the outcome result is not on the basis of truthfulness and honesty then justice wont have prevailed.