The surprising ending to the story provides a reversal of fortunes for both Rainsford and Zaroff. When Rainsford survives the plunge from the cliff and then shows up in Zaroff's bedroom, the general graciously concedes the contest.
"I congratulate you," he said. "You have won the game."
Zaroff would probably have honored the terms of the hunt and provided Rainsford with safe passage off the island. But the past three days as the hunted prey of Zardoff has hardened Rainsford, and he wants revenge. The old hunt will continue, Rainsford warns the Cossack. "I am still a beast at bay." Zaroff understands and he seems happy with the prospect of another human hunt--even if he is to now be the prey.
"Splendid! One of us is to furnish a repast for the hounds. The other will sleep in this very excellent bed. On guard, Rainsford..."
The final line of the short story provides the answers to your questions.
He had never slept in a better bed, Rainsford decided.
Rainsford is the only survivor: He has won the hunt, apparently killing Zaroff and possibly even feeding him to the dogs. Rainsford, who considers Zaroff a murderer, sleeps the sleep of the dead. He has won the hunt, but unlike Zaroff, Rainsford will probably be satisfied with his trophy--Zaroff, a murderer who has tried to kill him--and not grow to love it like Zaroff.