[R] Please help translate this program in python to R.

[Boris Steipe]

See my response to the C++ question you posted a minute later.

B.




> On 2019-12-15, at 05:35, Александр Дубровский <dubrovvsskkyy using gmail.com> wrote:
> 
> # Iterative Merge sort (Bottom Up)
> 
> # Iterative mergesort function to
> # sort arr[0...n-1]
> def mergeSort(a):
> 
>    current_size = 1
> 
>    # Outer loop for traversing Each
>    # sub array of current_size
>    while current_size < len(a) - 1:
> 
>        left = 0
>        # Inner loop for merge call
>        # in a sub array
>        # Each complete Iteration sorts
>        # the iterating sub array
>        while left < len(a)-1:
> 
>            # mid index = left index of
>            # sub array + current sub
>            # array size - 1
>            mid = left + current_size - 1
> 
>            # (False result,True result)
>            # [Condition] Can use current_size
>            # if 2 * current_size < len(a)-1
>            # else len(a)-1
>            right = ((2 * current_size + left - 1,
>                    len(a) - 1)[2 * current_size
>                          + left - 1 > len(a)-1])
> 
>            # Merge call for each sub array
>            merge(a, left, mid, right)
>            left = left + current_size*2
> 
>        # Increasing sub array size by
>        # multiple of 2
>        current_size = 2 * current_size
> 
> # Merge Function
> def merge(a, l, m, r):
>    n1 = m - l + 1
>    n2 = r - m
>    L = [0] * n1
>    R = [0] * n2
>    for i in range(0, n1):
>        L[i] = a[l + i]
>    for i in range(0, n2):
>        R[i] = a[m + i + 1]
> 
>    i, j, k = 0, 0, l
>    while i < n1 and j < n2:
>        if L[i] > R[j]:
>            a[k] = R[j]
>            j += 1
>        else:
>            a[k] = L[i]
>            i += 1
>        k += 1
> 
>    while i < n1:
>        a[k] = L[i]
>        i += 1
>        k += 1
> 
>    while j < n2:
>        a[k] = R[j]
>        j += 1
>        k += 1
> 
> 
> # Driver code
> a = [12, 11, 13, 5, 6, 7]
> print("Given array is ")
> print(a)
> 
> mergeSort(a)
> 
> print("Sorted array is ")
> print(a)
> 
> # Contributed by Madhur Chhangani [RCOEM]
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.