def merge$($arr$,$ start, mid, end$)$:

start$2=$ mid $+1$

if arr$[$mid$]<=$ arr$[$start$2]$: # If the two subarrays are already sorted, no need to merge

return

while start $<=$ mid and start$2<=$ end:

if arr$[$start$]<=$ arr$[$start$2]$:

start $+=1$

else:

value $=$ arr$[$start$2]$

index $=$ start$2$

# Shift elements in the first subarray to the right by one position

while index $!=$ start:

arr$[$index$]=$ arr$[$index $-1]$

index $-=1$

arr$[$start$]=$ value # Insert the smaller value at the correct position

start $+=1$

mid $+=1$

start$2+=1$

def mergeSort$($arr$)$:

n $=$ len$($arr$)$

curr$\_$size $=1$

while curr$\_$size $<$ n $-1$:

left$\_$start $=0$

while left$\_$start $<$ n $-1$:

# Find ending point of left subarray

mid $=$ min$($left$\_$start $+$ curr$\_$size $-1,$ n $-1)$

# Find starting point of right subarray

right$\_$end $=$ min$($left$\_$start $+2*$ curr$\_$size $-1,$ n $-1)$

# Merge subarrays arr$[$left$\_$start...mid$]$ and arr$[$mid$+1...$right$\_$end$]$

merge$($arr$,$ left$\_$start, mid, right$\_$end$)$

left$\_$start $+=2*$ curr$\_$size

curr$\_$size $*=2$

if $\_\_$name$\_\_==\text{'}\_\_$main$\_\_\text{'}$:

arr $=[12,11,13,5,6,7]$

mergeSort$($arr$)$

print$("$Sorted array:", arr$)$

calculate the time complexity for the code above.