mergesort

问题 I've been implementing a mergesort (from interactivepython) in Python/C++. The code fully works, but my issue is that I can't seem to figure out why a particular portion of the code actually does work. Code is: def mergeSort(alist): if len(alist)>1: mid = len(alist)//2 lefthalf = alist[:mid] righthalf = alist[mid:] mergeSort(lefthalf) mergeSort(righthalf) i=0 j=0 k=0 while i<len(lefthalf) and j<len(righthalf): if lefthalf[i]<righthalf[j]: alist[k]=lefthalf[i] i=i+1 else: alist[k]=righthalf[j]

问题 I've been working on an assignment for my Procedural Programming class where we are provided with a merge-sort program that does not function completely. It performs a merge-sort on arrays with an even number of integers, but throws a segmentation fault with an odd number of integers. I understand how the sorting works, and that the segmentation fault is being thrown because the odd number is causing the segmentation fault because the array is being over-filled somehow. I also understand that

问题 just a quick note, this is not homework. I'm just trying to brush up on my algorithms. I'm playing around with MergeSort in C# and I've written a recursive method that can sort based on Generics: class SortAlgorithms { public T[] MergeSort<T> (T[] unsortedArray) where T : System.IComparable<T> { T[] left, right; int middle = unsortedArray.Length / 2; left = new T[middle]; right = new T[unsortedArray.Length - middle]; if (unsortedArray.Length <= 1) return unsortedArray; for (int i = 0; i <

问题 I'm studying for a CS 125 final exam, and Big O Notation was covered (briefly). Given that: Mergesort has a Running Time Best Case of O(N lg(N)) and Running Time Worst Case of O(N lg (N)) There are 32 floating point values, initially in random order, stored in a double array How many total calls(activations) to mergesort will there be if the array is to be sorted? Assume the base case sorts a single value. I would go ahead and say simply plug in 32 to the worst case or best case (as mergesort

问题 Going back over my basic ADT stuff here to revise for an interview, and trying to kill two birds with one stone by learning Java while I am. Attempting to write a simple algorithm for a merge sort with a generic linked list ( which I am creating myself). It's proving to be far more difficult than I had first imagined ! Can anyone help me out please ? I will start out working on the basics and will update this post as I get further in. My code for the generic linked list is as follows : public

问题 I searched and couldn't find in which version the TimSort actually replaced the MergeSort in collections.sort() method. If anyone can let me know the exact version for JDK7 it would be a great help. 回答1: TimSort has been used in Java 7 right from the release. To be more specific, it has been added in Java 7, beta 70. It might be worth noting that this is still a modified merge sort, just having more modifications being more efficient than the modified merge sort that has been used in previous

问题 I was working on one of the problems on Leetcode (problem 21). It asks me to merge two sorted linked lists and return it as a new list, and it gives pre-typed code like this. # Definition for singly-linked list. # class ListNode(object): # def __init__(self, x): # self.val = x # self.next = None class Solution(object): def mergeTwoLists(self, l1, l2): """ :type l1: ListNode :type l2: ListNode :rtype: ListNode """ I did some test before formally solving merging problem. I input l1 as following

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 6 years ago . I'm trying to write a merge sort program with pointers, and it is near to working good, but there is the problem that in the output there are some '0' instead of some of the numbers of the sorted array. For testing the code you have to write a txt file prova.txt in which there is the array, one number for line.

问题 Given this problem: Write a function that takes two date of birth structures as input and returns -1, 0, 1 if the first parameter is less than, equal to or greater than the second parameter respectively. Using your function, write a recursive mergeSort program to sort the linked list of student records in increasing order of their age (do not use arrays, use linked list only). here is what I wrote: #include <stdio.h> #include <stdlib.h> #include <string.h> /*Recursive Merge Sort to sort

问题 I was trying iterative merge sort , but am stuck at at conditions when input length is not 2^x. like int[] A ={4,5,1,254,66,75,12,8,65,4,87,63,53,8,99,54,12,34}; public class MergeSort { public static void sort(int[] A) { System.out.println("Log(A.len):"+log(A.length, 2)); for (int i = 0; i < log(A.length, 2); i++) { //log A.len int r = 2 << i; //2^i int mid = r >>> 1; for (int j = 0; j+r < A.length; j = j + r) { System.out.print("offset:" + j + " mid:" + (j + mid) + " r:" + (j + r)); merge(A