On Mon, 09 Mar 2020 07:32:28 GMT
Jan Panteltje  wrote:

> Nice, I like linked lists.

 All right time to share an ancient hack (that I actually used once).

 You have a single linked list which you wish was a double linked
list but due to resource limits you can't simply create a double linked
list and copy the data you have to convert it in place without using any
extra space. How ? (You may assume the list uses integers as pointers).
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thinking space
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 Instead of 'next' the pointer field contains 'next xor previous'
provided you know where you came from 'last' you go to 'last xor pointer'
to continue in the same direction.

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Steve O'Hara-Smith                          |   Directable Mirror Arrays
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