mergesort

So I have a MergeSort algorithm and I want to combine MergeSort with Insertion sort to reduce the overhead of merging, the question is how? I want to sort the segments using insertion sort and then merge. public class mergesorttest{ public static void main(String[]args){ int d[]= {10,2,3,4,5,6,5,4,3,5,6,7,1}; mergeSort(d,0,d.length); for(int x:d) System.out.print(x+" "); System.out.println(); } static void mergeSort(int f[],int lb, int ub){ //termination reached when a segment of size 1 reached -lb+1=ub if(lb+1<ub){ int mid = (lb+ub)/2; mergeSort(f,lb,mid); mergeSort(f,mid,ub); merge(f,lb,mid

I use recursive merge sort for sorting a link list, but during the merge sort I would like to delete duplicates. Anyone has insight in how to accomplish this? I am using C code. In merge sort you take two (or more) already-sorted lists repeatedly apply the following rules: find the lesser/least of the items of the top of each of the input lists, choosing any of the lowest items if there is a tie remove that item from its list add it to your output list To remove duplicates, you simply modify the rules very slightly: find the lesser/least of the items of the top of each of the input lists,

This generates a Segmentation Fault: 11 and I have no clue why. Before I get into it, here's the code: import numpy.random as nprnd import heapq import sys sys.setrecursionlimit(10**6) def rlist(size, limit_low, limit_high): for _ in xrange(size): yield nprnd.randint(limit_low, limit_high) def iterator_mergesort(iterator, size): return heapq.merge( iterator_mergesort( (iterator.__next__ for _ in xrange(size/2)), size/2), iterator_mergesort( iterator, size - (size/2)) ) def test(): size = 10**3 randomiterator = rlist(size, 0, size) sortediterator = iterator_mergesort(randomiterator, size)

Java 6's mergesort implementation in Arrays.java uses an insertion-sort if the array length is less than some threshold. This value is hard-coded to 7. As the algorithm is recursive, this eventually happens many times for a large array. The canonical merge-sort algorithm does not do this, just using merge-sort all the way down until there is only 1 element in the list. Is this an optimisation? If so, how is it supposed to help? And why 7 ? The insertion sort (even of <=7 things) increases the number of comparisons required to sort a large array dramatically - so will add cost to a sort where

I found this code online: def merge(left, right): result = [] i ,j = 0, 0 while i < len(left) and j < len(right): if left[i] <= right[j]: result.append(left[i]) i += 1 else: result.append(right[j]) j += 1 result += left[i:] result += right[j:] return result def mergesort(list): if len(list) < 2: return list middle = len(list) / 2 left = mergesort(list[:middle]) right = mergesort(list[middle:]) return merge(left, right) It works 100% when I run it. I just do not really get how the merge sort works or how the recursive function is able to properly order both a left and a right. I believe that

I'm trying to get some practice with sorting in Java. I'm working on the merge sort now... Eclipse is outputting Out Of Memory Error: Java Heap space , but I'm not sure how to debug that. I feel like my code is okay- any thoughts? import java.util.ArrayList; import java.util.List; public class Sorts { List<Integer> initialList; public Sorts() { initialList = new ArrayList<Integer>(); initialList.add(2); initialList.add(5); initialList.add(9); initialList.add(3); initialList.add(6); System.out.print("List: ["); for (int values : initialList) { System.out.print(values); } System.out.println("]")