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sera (小狮子||混在纽约) 于 (Thu Jul 13 14:31:49 2006) 提到:
not sure whether u guys've come across these before...
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Sample of D. E. Shaw puzzles
You have twelve coins, one of which is known is known to be counterfeit and
therefore heavier or lighter than all the others. You also have a balance-pan
scale. In three weighings determine which coin is counterfeit and whether it
is heavier or lighter.
You have ten big vats of 10-gram coins