Assume there's 4 monks - 2 pure, 2 corrupt. From the perspective of one corrupt monk, he sees two pures and one corrupt. The guru says "I see a corrupt soul." With this, he thinks: "If I am pure, the corrupt one will now know he is corrupt, and so he will commit suicide tonight." When he notices that the corrupt monk does not commit suicide on the first night, he realizes that the monk must see another corrupt soul, who would be none other than himself. Both corrupt monks go through this thought process. And so the two of them would commit suicide on the second night.
This logic continues for as long as you extend the numbers. If there were 100 corrupt monks, they would commit suicide on the 100th night. From the perspective of a third monk, he figures that two corrupt monks can discover their purity by the second night if he himself is pure. From a forth, he figures that three can discover their purity by the third night, etc.
100 men with symbols on their foreheads are trapped in a guarded room. Apart from them, the room is empty. They are all very bright; they will instantly find any available logical solution. There is no way to escape the room besides the following: Every night at a fixed time, the guards will let through any man who knows the symbol on his forehead. They will be shot if they answer incorrectly. None of them can communicate with each other in any fashion. Everything just stated is known to all 100 men. It is the first day. 50 of the group bear Squares on their foreheads, while the other 50 bear Stars. Nobody knows this new string of information besides the guards; to every man, there can be 49 Squares and 51 Stars, or vice versa. He may also bear a unique symbol. No man knows his own symbol yet. A guard's voice booms in the room: "I see someone with a star symbol." With only this information, how many people leave the room, and on what night? The answer isn't BS, and its not "no one"
"I'm only back temporarily. Don't get too excited now. :P" NU NU NUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUNOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO
Assume there's 4 monks - 2 pure, 2 corrupt.
From the perspective of one corrupt monk, he sees two pures and one corrupt. The guru says "I see a corrupt soul." With this, he thinks: "If I am pure, the corrupt one will now know he is corrupt, and so he will commit suicide tonight." When he notices that the corrupt monk does not commit suicide on the first night, he realizes that the monk must see another corrupt soul, who would be none other than himself. Both corrupt monks go through this thought process. And so the two of them would commit suicide on the second night.
This logic continues for as long as you extend the numbers. If there were 100 corrupt monks, they would commit suicide on the 100th night. From the perspective of a third monk, he figures that two corrupt monks can discover their purity by the second night if he himself is pure. From a forth, he figures that three can discover their purity by the third night, etc.