Wonder why it should be big challenge as it is stated here, here is a straightforward implementation in Java with out any “clever tricks”. //The main function public static Node merge_sort(Node head) { if(head == null || head.next == null) return head; Node middle = getMiddle(head); //get the middle of the list Node left_head = … Read more
Quicksort has O(n2) worst-case runtime and O(nlogn) average case runtime. However, it’s superior to merge sort in many scenarios because many factors influence an algorithm’s runtime, and, when taking them all together, quicksort wins out. In particular, the often-quoted runtime of sorting algorithms refers to the number of comparisons or the number of swaps necessary … Read more
public static int[] merge(int[] a, int[] b) { int[] answer = new int[a.length + b.length]; int i = 0, j = 0, k = 0; while (i < a.length && j < b.length) answer[k++] = a[i] < b[j] ? a[i++] : b[j++]; while (i < a.length) answer[k++] = a[i++]; while (j < b.length) answer[k++] = … Read more
Knuth left this as an exercise (Vol 3, 5.2.5). There do exist in-place merge sorts. They must be implemented carefully. First, naive in-place merge such as described here isn’t the right solution. It downgrades the performance to O(N2). The idea is to sort part of the array while using the rest as working area for … Read more
I got it guys 🙂 While copying main array into auxiliary array in the Merge function, there was bug in the index. int size = hi – lo + 1; int *aux_arr = new int[size]; for(i = 0, j = lo;i <= size;i++){ aux_arr[i] = first_arr[j++]; } Here’s the code with correction. Also as the … Read more
include <time.h> include <stdio.h> int main(){ clock_t start = clock(); // Execuatable code clock_t stop = clock(); double elapsed = (double)(stop – start) * 1000.0 / CLOCKS_PER_SEC; printf(“Time elapsed in ms: %f”, elapsed); }
Your problem is in the merge function: you exceed the local variable c. long c[30]; maybe there are more problems, that is the first I notice. EDIT Try this: find the differences… #include <map> #include <vector> #include <fstream> #include <iostream> #include <time.h> using namespace std; void merge(vector<long> &,long ,long , long ); void divide(vector<long> &arr,long … Read more