Commit Graph

56 Commits

Author SHA1 Message Date
Tim Peters 0cd53a6c37 Added new heapreplace(heap, item) function, to pop (and return) the
currently-smallest value, and add item, in one gulp.  See the second
N-Best algorithm in the test suite for a natural use.
2002-08-03 10:10:10 +00:00
Tim Peters aa7d24319e Minor fiddling, including a simple class to implement a heap iterator
in the test file.  I have docs for heapq.heapify ready to check in, but
Jack appears to have left behind a stale lock in the Doc/lib directory.
2002-08-03 02:11:26 +00:00
Tim Peters 28c25527c2 Hmm! I thought I checked this in before! Oh well.
Added new heapify() function, which transforms an arbitrary list into a
heap in linear time; that's a fundamental tool for using heaps in real
life <wink>.

Added heapyify() test.  Added a "less naive" N-best algorithm to the test
suite, and noted that this could actually go much faster (building on
heapify()) if we had max-heaps instead of min-heaps (the iterative method
is appropriate when all the data isn't known in advance, but when it is
known in advance the tradeoffs get murkier).
2002-08-02 21:48:06 +00:00
Tim Peters d2cf1ab0e2 check_invariant(): Use the same child->parent "formula" used by heapq.py. 2002-08-02 19:41:54 +00:00
Tim Peters d9ea39db84 Don't use true division where int division was intended. For that matter,
don't use division at all.
2002-08-02 19:16:44 +00:00
Guido van Rossum 0b19178736 Adding the heap queue algorithm, per discussion in python-dev last
week.
2002-08-02 18:29:53 +00:00