/sorts/merge_sort_fastest.py is NOT fast at all about python HOT 12 CLOSED

I think we could rename merge_sort_fastest.py to something else as it is not fast at all neither resembles merge sort. What do you think?

from python.

Yes! @tom5610 you are right. The usage of inbuilt functions is not right here to make program faster.
By the way the Python/sorts/merge_sort.py is more faster than this.

from python.

It's also not merge sort. It's some weird two-pronged version of selection sort.

from python.

# Merges two subarrays of arr[]. 
# First subarray is arr[l..m] 
# Second subarray is arr[m+1..r] 
def merge(arr, l, m, r): 
    n1 = m - l + 1
    n2 = r- m 
  
    # create temp arrays 
    L = [0] * (n1) 
    R = [0] * (n2) 
  
    # Copy data to temp arrays L[] and R[] 
    for i in range(0 , n1): 
        L[i] = arr[l + i] 
  
    for j in range(0 , n2): 
        R[j] = arr[m + 1 + j] 
  
    # Merge the temp arrays back into arr[l..r] 
    i = 0     # Initial index of first subarray 
    j = 0     # Initial index of second subarray 
    k = l     # Initial index of merged subarray 
  
    while i < n1 and j < n2 : 
        if L[i] <= R[j]: 
            arr[k] = L[i] 
            i += 1
        else: 
            arr[k] = R[j] 
            j += 1
        k += 1
  
    # Copy the remaining elements of L[], if there 
    # are any 
    while i < n1: 
        arr[k] = L[i] 
        i += 1
        k += 1
  
    # Copy the remaining elements of R[], if there 
    # are any 
    while j < n2: 
        arr[k] = R[j] 
        j += 1
        k += 1
  
# l is for left index and r is right index of the 
# sub-array of arr to be sorted 
def mergeSort(arr,l,r): 
    if l < r: 
  
        # Same as (l+r)/2, but avoids overflow for 
        # large l and h 
        m = (l+(r-1))/2
  
        # Sort first and second halves 
        mergeSort(arr, l, m) 
        mergeSort(arr, m+1, r) 
        merge(arr, l, m, r) 

PLEASE CHECK THIS. i HOPE IT HELPS

from python.

@brunohadlich ,
I think we should have only one merge_sort file not merge_sort.py and merge_sort_fastest.py. I will inspect these two files and get back to you. What do you think?

from python.

I agree, it's been a long time since my last contribution to this project as I'm busy with other tasks. Feel free to discuss and apply the best solution.

from python.

It's ok, I just started on this project. I will spend more time on it and keep it posted here.

from python.

Hi @brunohadlich
I looked at these two files:

• merge_sort.py
• merge_sort_fastest.py

The one that I recommend to keep is merge_sort.py, the other one is NOT merge sort algorithm. It's something else that works fine but for the sake of algorithm education is misleading.

Let me know if there is any more work to be done on this issue, otherwise after deleting the file 'merge_sort_fastest.py' we can close this issue.

Note: @cclauss please look at this message.

from python.

Just raise a PR for the same

from python.

Please open a PR that renames merge_sort_fastest.py to unknown_sort.py.

from python.

OK sure, thank you.

from python.

PR is created: #1612.

from python.