Hithomelabs/Princeton1
6
0
Fork 3
Code Issues Pull Requests 1 Actions Packages Projects Releases Wiki Activity

kruti-working-branch #14

Closed
kruti wants to merge 15 commits from kruti/Princeton1:kruti-working-branch into main
pull from: kruti/Princeton1:kruti-working-branch
merge into: Hithomelabs:main
Conversation 0 Commits 15 Files Changed 11 +19 -14
1 changed files with 19 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files
Showing only changes of commit b8da0cb3b1 - Show all commits

25
module6/src/main/java/com/hithomelabs/princeton1/module6/Merge.java
View File

@ -11,31 +11,36 @@ public class Merge<E> extends AbstractCustomSorts<E> {
} }
private void merge_sort(E[] arr, int low_index, int high_index){ private void merge_sort(E[] arr, int low_index, int high_index){
System.out.println(low_index + " " + high_index);
if(high_index - low_index > 0) { if(high_index - low_index > 0) {
int mid_index = low_index + (high_index - low_index)/2; int mid_index = low_index + (high_index - low_index)/2;
merge_sort(arr, low_index, mid_index); merge_sort(arr, low_index, mid_index);
merge_sort(arr, mid_index + 1, high_index); merge_sort(arr, mid_index + 1, high_index);
// Copy array // Copy array
E[] auxArr = (E[]) new Object[arr.length]; E[] auxArr = (E[]) new Object[high_index - low_index + 1];
hitanshu marked this conversation as resolved Outdated
hitanshu commented 2025-02-09 17:33:44 +00:00
Outdated
Review
Copy Link

Making a new aux arry with each recursive call is expensive

Making a new aux arry with each recursive call is expensive
System.arraycopy(arr, 0, auxArr, 0, arr.length); int index = 0;
for(int i=low_index; i<= high_index; i++)
auxArr[index++] = arr[i];
// Sort // Sort
int low_index_ptr = low_index; int low_index_ptr = 0;
int high_index_ptr = mid_index + 1; int mid_index_ptr = (auxArr.length - 1)/2;
for(int i=low_index; i<= high_index; i++){ int high_index_ptr = mid_index_ptr + 1;
if(low_index_ptr > mid_index) if(!less((Comparable<E>) auxArr[mid_index_ptr], auxArr[high_index_ptr])) {
arr[i] = auxArr[high_index_ptr++]; for (int i = low_index; i <= high_index; i++) {
else if(high_index_ptr > high_index) if (low_index_ptr > mid_index_ptr) {
arr[i] = auxArr[high_index_ptr];
high_index_ptr++;
} else if (high_index_ptr >= auxArr.length)
arr[i] = auxArr[low_index_ptr++]; arr[i] = auxArr[low_index_ptr++];
else if(less((Comparable<E>) auxArr[low_index_ptr], auxArr[high_index_ptr])) else if (less((Comparable<E>) auxArr[low_index_ptr], auxArr[high_index_ptr]))
arr[i] = auxArr[low_index_ptr++]; arr[i] = auxArr[low_index_ptr++];
else else
arr[i] = auxArr[high_index_ptr++]; arr[i] = auxArr[high_index_ptr++];
} }
} }
} }
}
} }