How can we Implement Bisect Python functionality in PHP
Implement function bisect_left($arr, $item);
as a pure-PHP routine to do a binary-bisection search for
the position at which to insert $item into $list, maintaining the sort
order therein.
Assumptions:
Assume that $arr is already sorted by whatever
comparisons would be yielded by the stock PHP < operator, and that it's
indexed on ints.
The function should return an int, representing the index within the
array at which $item would be inserted to maintain the order of the
array. The returned index should be below any elements in $arr equal to
$item, i.e., the insertion index should be "to the left" of anything
equal to $item.
Search routine should not be linear! That is, it should honor the
name, and should attempt to find it by iteratively bisecting the list
and comparing only around the midpoint.