Interview Question


2 lists, find the common elements amongst the list. Do it

  w/ and w/o external storage, as fast as possible.

Interview Answer

2 Answers


1) With external storage Using two stacks to push all elements into them. Then pop until get different elements; 2) Without external storage Calculate the length of two lists, l1 and l2, using two pointers which p2 is l2 - l1 steps ahead p1(suppose l2 > l1). Walk through list until find same element.

Anonymous on Apr 10, 2013

in python: r=[x for x in l1 if x in l2]

Anonymous on Feb 1, 2014

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