More Hat Puzzles
I believe there is one more minor thing to add. After fisherman C realizes his hat is black and announces that fisheman B can conclude his hat is white - otherwise fisherman C could not make this conclusion
Actually, B could shout out the colour of his hat in very short order - after C or D had told him.
It is not C only who waits for an immediate response. A and B are waiting also. Should there be one (it could come only from D if B and C wear the same color), A screams the same color, B and C - the opposite one. If none screams right away, C screams the color opposite to the one he sees on B and B then screams the color opposite to the one he heard.
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