29. Yes, exactly 1618 of the 625415 solutions have repeated words. For example:
A C C E S S A S S E R T B E G G E D M A G M A S T R A D E S
M O O L A H J A I L E R R E A L E R O N L I N E R E V I S E
I M M U N E U G L I F Y A R T E R Y D I O X I N O T I O S E
N E E D E D G E O D E S W I E N I E A S S E S S T R A D E S
O T T E R S A S S E R T L E S S E R L E S S E E H O N E S T
30. The use of a single compressed trie both horizontally and vertically leads to a very pretty algorithm, which needs only 120 Mμ to find all 541,968 solutions. De Morgan’s example isn’t among them, because the proper name ‘ELLEN’ doesn’t qualify as a word by our conventions. But some of the squares might be “meaningful,” at least ...
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