#Arithmetic_arranger.py

import re

def arithmetic_arranger(problems, show_results = False):

### Different lines to print
first_number = list()
second_number = list()
operator = list()



# Limit of 5 problems solution
if len(problems) > 5:
return "Error: Too many problems."

#Breaking down the problem
for problem in problems:
problem = problem.split()
first_number.append(problem[0])
second_number.append(problem[2])
operator.append(problem[1])

# Looking for appropiate operators
for items in problems:
if "/" in items:
return "Error: Operator must be '+' or '-'."
if "*" in items:
return "Error: Operator must be '+' or '-'."

# Looking for letters
for problem in problems:
search = re.search("[A-Za-z]+", problem)
if search :
return "Error: Numbers must only contain digits."

# Checking out length - Max 4 digits
for operand in problems:
operand = operand.split()
if len(operand[0]) > 4 or len(operand[2]) > 4:
return "Error: Numbers cannot be more than four digits."

string_1 = []
string_2 = []
string_3 = []
string_4 = []



#Arranging line 1
for x in range (len(first_number)):
if len(first_number[x]) > len(second_number[x]):
string_1.append(" " + first_number[x])
else:
string_1.append(" " * (len(second_number[x]) - len(first_number[x]) + 2 ) + first_number[x])

#Arranging line 2
for x in range(len(second_number)):
if len(second_number[x]) > len(first_number[x]):
string_2.append( operator[x] + " " + second_number[x])

else:
string_2.append(operator[x] + " " * (len(first_number[x]) - len(second_number[x]) + 1) + second_number[x])

# Arranging line 3
for x in range(len(second_number)):
string_3.append("-" * (max(len(first_number[x]), len(second_number[x])) + 2))



if show_results == True:

for x in range(len(first_number)):
if operator[x] == "+":
sumx = str(int(first_number[x]) + int(second_number[x]))
else:
sumx = str(int(first_number[x]) - int(second_number[x]))

if len(sumx) > max(len(first_number[x]), len(second_number[x])):
string_4.append(" " + sumx )
else:
string_4.append(" " * (max(len(first_number[x]), len(second_number[x])) -len(sumx) + 2) + sumx)


arranged_problems = " ".join(string_1) + "\n" + " ".join(string_2) + "\n" + " ".join(string_3) + "\n" + " ".join(string_4)
return arranged_problems

else:
arranged_problems = " ".join(string_1) + "\n" + " ".join(string_2) + "\n" + " ".join(string_3)
return arranged_problems