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In the merge sort algorithm, this subroutine is typically used to merge two sub-arrays A[lo..mid], A[mid+1..hi] of a single array A. This can be done by copying the sub-arrays into a temporary array, then applying the merge algorithm above. [1] The allocation of a temporary array can be avoided, but at the expense of speed and programming ease.
Suppose that such an algorithm existed, then we could construct a comparison-based sorting algorithm with running time O(n f(n)) as follows: Chop the input array into n arrays of size 1. Merge these n arrays with the k-way merge algorithm. The resulting array is sorted and the algorithm has a running time in O(n f(n)).
As of Perl 5.8, merge sort is its default sorting algorithm (it was quicksort in previous versions of Perl). [28] In Java, the Arrays.sort() methods use merge sort or a tuned quicksort depending on the datatypes and for implementation efficiency switch to insertion sort when fewer than seven array elements are being sorted. [29]
The outer loop of block sort is identical to a bottom-up merge sort, where each level of the sort merges pairs of subarrays, A and B, in sizes of 1, then 2, then 4, 8, 16, and so on, until both subarrays combined are the array itself.
One implementation can be described as arranging the data sequence in a two-dimensional array and then sorting the columns of the array using insertion sort. The worst-case time complexity of Shellsort is an open problem and depends on the gap sequence used, with known complexities ranging from O ( n 2 ) to O ( n 4/3 ) and Θ( n log 2 n ).
The sort-merge join (also known as merge join) is a join algorithm and is used in the implementation of a relational database management system. The basic problem of a join algorithm is to find, for each distinct value of the join attribute, the set of tuples in each relation which display that value. The key idea of the sort-merge algorithm is ...
Merge-insertion sort also performs fewer comparisons than the sorting numbers, which count the comparisons made by binary insertion sort or merge sort in the worst case. The sorting numbers fluctuate between n log 2 n − 0.915 n {\displaystyle n\log _{2}n-0.915n} and n log 2 n − n {\displaystyle n\log _{2}n-n} , with the same leading ...
The summaries (arrays) output by the algorithm are mergeable, in the sense that combining summaries of two streams s and r by adding their arrays keywise and then decrementing each counter in the resulting array until only k keys remain results in a summary of the same (or better) quality as compared to running the Misra-Gries algorithm over ...