what is the relationship between Ralph and the other characters by the end of the book?
Ralph's relationship with the other boys at the end of the book borders on estrangement to open hostility, in the case of Jack. Ralph's popularity begins to decline after Jack leaves the tribe for good. Ralph and Piggy notice that some of the other older boys have disappeared until only Ralph, Piggy, Simon, Sam, and Eric remain.
After Piggy's death, Jack threatens Ralph:
"See? See?" That's what you'll get! There isn't a tribe for you anymore!" (181)
Ralph becomes 'public enemy number one' as Jack even forces Samneric to join his tribe, using torture to coerce them. The end of the novel is as violent as it is chaotic; Jack has formed a hunting party out of all of Ralph's former friends and tribe mates, and Ralph hides alone, frightened for his life.