While it appears evil triumphs in the end, give examples including quotes where goodness does exist in the novel (3 ex for Ralph and 3 for Piggy).

He came to himself with a jolt. Piggy and the other two were by him. They were laden with fruit.
“I thought perhaps,” said Piggy, “we ought to have a feast, kind of.”
The three boys sat down. They had a great mass of the fruit with them and all of it properly ripe. They grinned at Ralph as he took some and began to eat.
“Thanks,” he said. Then with an accent of pleased surprise—“Thanks!”