As many others have noted, translating the "conditions" to firearms with other operating modes is a challenge. If one wants to do it, then one might logically derive the following from Cooper's designations:
Condition 0: The gun is 100% ready to fire, with the hammer (or striker) pre-loaded. For guns that cock their own hammer as part of the operation of firing, the state of the gun in the middle of a string of fire.
Condition 1: The gun has a round chambered and the firing mechanism charged/cocked/under tension or compression AND there is a safety which makes pulling the trigger insufficient to discharge the firearm. Guns without a safety device are unable to achieve this condition.
Condition 2: The gun has a round chambered, but the firing mechanism is not cocked/under tension or compression/charged. The firing mechanism might be charged manually (cocking) or as part of a DA trigger pull. A revolver with the hammer down is in this condition, as is a DAO semi-auto with the hammer down.
Condition 2.5: Hammer is down on a live round, safety is on. Firing the gun will require deactivating the safety and charging the firing system. Impossible with a 1911, but possible with some other guns (including, but not limited to, guns like the M9 that have a combined safety/decocker).
Condition 3: Loaded magazine, hammer down on empty chamber. "Israeli carry."
Condition 3.5: See 2.5, but with no round chambered.
Condition 4: No rounds in pistol.
Condition 4.5: See 3.5, but with a safety on.
The hardest question would be how to characterize striker-fired pistols that partially charge the firing mechanism, but still require some additional energy from the trigger and have no safety. They are either going to be in Condition 0 or Condition 2 when they are loaded. From a functional point of view, those with short-ish trigger pulls, like Glocks, are basically in Condition 0 when loaded and at rest. But that would be a grey area.
All the above is not offered as "the answer." It isn't. It's just a little mental exercise.