Function _log2

recipes/Python/252123_Range_minimleast/recipe-252123.py:223–227

Make table of logs reach up to n and return floor(log_2(n)).

(n)

_logtable = [None,0]
def _log2(n):
    """Make table of logs reach up to n and return floor(log_2(n))."""
    while len(_logtable) <= n:
        _logtable.extend([1+_logtable[-1]]*len(_logtable))
    return _logtable[n]

# if run as "python lca.py", run tests on random data
# and check that RangeMin's results are correct.