Question

Python3

I am having trouble with my indentation while running this program. Thanks for the help.

#4-way mergeSort

def merge(A, l,m2,m1, m3, h):

n1 = m2 - l + 1#calculating length of subarrays

n2 = m1- m2

n3 = m3-m1

n4 = h-m3

Ln = m1-l+1

Rn = h-m1

# creating temporary arrays

a = [0] * (n1)

b = [0] * (n2)

c = [0] * (n3)

d = [0] * (n4)

L = [0] * (Ln)

R = [0] * (Rn)

# Copy data to temp arrays L[] and R[]

for i in range(0 , n1):

a[i] = A[l + i]

for i in range(0 , n2):

b[i] = A[m2+1 + i]

for i in range(0 , n3):

c[i] = A[m1+1 + i]

for i in range(0 , n4):

d[i] = A[m3+1 + i]

i1=0

i2=0

k=0

while i1 < n1 and i2 < n2 :#merging first two part

if a[i1] <= b[i2]:

L[k] = a[i1]

i1 += 1

else:

L[k] = b[i2]

i2 += 1

k += 1

while i1 < n1:

L[k] = a[i1]

i1 += 1

k += 1

while i2 < n2:

L[k] = b[i2]

i2 += 1

k += 1

i1=0

i2=0

k=0

while i1 < n3 and i2 < n4 :

if c[i1] <= d[i2]:

R[k] = c[i1]

i1 += 1

else:

R[k] = d[i2]

i2 += 1

k += 1

while i1 < n3:

R[k] = c[i1]

i1 += 1

k += 1

# Copy the remaining elements of R[], if there

# are any

while i2 < n4:

R[k] = d[i2]

i2 += 1

k += 1

i=0

j=0

k=l

while i < Ln and j < Rn :

if L[i] <= R[j]:

A[k] = L[i]

i += 1

else:

A[k] = R[j]

j += 1

k += 1

while i < Ln:

A[k] = L[i]

i += 1

k += 1

# Copy the remaining elements of R[], if there

# are any

while j < Rn:

A[k] = R[j]

j += 1

k += 1

def mergeSort(A,low,high):

if low < high:

m1 = int((low+(high))/2)

m2 = int((low+m1)/2)

m3 = int(((m1+1)+high)/2)

mergeSort(A, low, m2)

mergeSort(A, m2+1, m1)

mergeSort(A, m1+1, m3)

mergeSort(A, m3+1, high)

merge(A, low,m2, m1,m3, high)

# New Code

# Creating a new list for input

A = []

# Read input from the file

with open('input.txt','r') as inp_f:

for line in inp_f:

for word in line.split():

A.append(int(word))

# Setting array size i.e. the first value of input in the file

arr_size = A[0]

# Creating a new array by removing first value of size.

A = A[1:]

mergeSort(A,0,arr_size-1)

print ("Your sorted result is stored in output.txt")

# Writing to the file.

with open('output.txt', 'w') as out_f:

for item in A:

out_f.write("%s " % item)

Answer 1

def merge(A, l,m2,m1, m3, h):
n1 = m2 - l + 1#calculating length of subarrays
n2 = m1- m2
n3 = m3-m1
n4 = h-m3
Ln = m1-l+1
Rn = h-m1
# creating temporary arrays
a = [0] * (n1)
b = [0] * (n2)
c = [0] * (n3)
d = [0] * (n4)
L = [0] * (Ln)
R = [0] * (Rn)
# Copy data to temp arrays L[] and R[]
for i in range(0 , n1):
a[i] = A[l + i]
for i in range(0 , n2):
b[i] = A[m2+1 + i]
for i in range(0 , n3):
c[i] = A[m1+1 + i]
for i in range(0 , n4):
d[i] = A[m3+1 + i]
i1=0
i2=0
k=0
while i1 < n1 and i2 < n2 :#merging first two part
if a[i1] <= b[i2]:
L[k] = a[i1]
i1 += 1
else:
L[k] = b[i2]
i2 += 1
k += 1
while i1 < n1:
L[k] = a[i1]
i1 += 1
k += 1
while i2 < n2:
L[k] = b[i2]
i2 += 1
k += 1
i1=0
i2=0
k=0
while i1 < n3 and i2 < n4 :
if c[i1] <= d[i2]:
R[k] = c[i1]
i1 += 1
else:
R[k] = d[i2]
i2 += 1
k += 1
while i1 < n3:
R[k] = c[i1]
i1 += 1
k += 1
# Copy the remaining elements of R[], if there
# are any
while i2 < n4:
R[k] = d[i2]
i2 += 1
k += 1
i=0
j=0
k=l
while i < Ln and j < Rn :
if L[i] <= R[j]:
A[k] = L[i]
i += 1
else:
A[k] = R[j]
j += 1
k += 1
while i < Ln:
A[k] = L[i]
i += 1
k += 1
# Copy the remaining elements of R[], if there
# are any
while j < Rn:
A[k] = R[j]
j += 1
k += 1
def mergeSort(A,low,high):
if low < high:
m1 = int((low+(high))/2)
m2 = int((low+m1)/2)
m3 = int(((m1+1)+high)/2)
mergeSort(A, low, m2)
mergeSort(A, m2+1, m1)
mergeSort(A, m1+1, m3)
mergeSort(A, m3+1, high)
merge(A, low,m2, m1,m3, high)
# New Code
# Creating a new list for input

A = []
# Read input from the file
with open('input.txt','r') as inp_f:
for line in inp_f:
for word in line.split():
A.append(int(word))
# Setting array size i.e. the first value of input in the file
arr_size = A[0]
# Creating a new array by removing first value of size.
A = A[1:]
mergeSort(A,0,arr_size-1)
print ("Your sorted result is stored in output.txt")
# Writing to the file.
with open('output.txt', 'w') as out_f:
for item in A:
out_f.write("%s " % item)