what was the major conflict in the story and how was it resolved

The number one conflict in the story involves man vs society, or the government against its people. A conflict of man vs man occurs between the tributes when they are forced to participate in the games, and there are a number of situations in which the tributes are pitted against nature. Internally, the tributes also have instances of internal conflicts as well.

The resolution of the story would occur when Katniss and Peeta decide to kill themselves rather than give into the government's rules.

I think its the war.