def infix_to_potfix(token_list):
"""
들어온 중위 표현식을 후위 표현식으로 변경
:param token_list:
:return: 후위 표현식
"""
prec = {'*': 3, '/': 3, '+': 2, '-': 2, '(': 1}
opStack = ArrayStack()
result = []
for token in token_list:
if isinstance(token, int):
result.append(token)
elif token == '(':
opStack.push(token)
elif token == ')':
while opStack.peek() != '(':
result.append(opStack.pop())
opStack.pop()
else:
if not opStack.isEmpty():
if prec[opStack.peek()] >= prec[token]:
result.append(opStack.pop())
opStack.push(token)
else:
opStack.push(token)
else:
opStack.push(token)
while not opStack.isEmpty():
result.append(opStack.pop())
print(result)
return result
class TestArrayStack(unittest.TestCase):
def setUp(self):
self.st = ArrayStack()
def tearDown(self):
del self.st
# default feature test - push, pop, peek
def test_01(self):
self.st.push(1)
self.st.push(2)
self.st.push(3)
self.assertEqual(self.st.peek(), 3)
self.assertEqual(self.st.pop(), 3)
self.assertEqual(self.st.peek(), 2)
self.assertEqual(self.st.pop(), 2)
self.assertEqual(self.st.peek(), 1)
self.assertEqual(self.st.pop(), 1)
# raise error when pop with empty stack
def test_02(self):
with self.assertRaises(IndexError) as cm:
self.st.pop()
self.assertEqual("stack is empty", str(cm.exception))
# test check empty
def test_03(self):
self.assertTrue(self.st.is_empty())
# test expand
def test_04(self):
self.assertEqual(len(self.st._array), 10)
for i in range(11):
self.st.push(i)
self.assertEqual(len(self.st._array), 20)
def test_peek(self):
# empty stack
stack = ArrayStack()
with self.assertRaises(StackException):
stack.peek()
# add one thing then peek. it should still be there
stack.push('a')
self.assertEqual(stack.peek(), 'a')
self.assertEqual(stack.peek(), 'a')
def solveMaze(row, column, maze):
stack = ArrayStack()
stack.push((row, column))
while not stack.isEmpty():
(row, column) = stack.peek()
if maze[row][column] == 'T':
return stack
elif maze[row][column] != '.':
maze[row][column] = '.'
counter = 0 ###adjacent cells based on changing x,y values so need 4 options
if row != 0 and not maze[row - 1][column] in ('*', '.'):
stack.push((row-1, column))
counter += 1
if row + 1 != maze.getHeight() and not maze[row + 1][column] in ('*', '.'):
stack.push((row + 1, column))
counter += 1
if column + 1 != maze.getWidth() and not maze[row][column + 1] in ('*', '.'):
stack.push((row, column + 1))
counter += 1
if column != 0 and not maze[row][column -1] in ('*', '.'):
stack.push((row, column - 1))
counter += 1
if counter == 0:
stack.pop()
return None
class StackQueue:
def __init__(self):
self.stack1 = ArrayStack()
self.stack2 = ArrayStack()
self.count = 0
def enqueue(self, item):
self.stack1.push(item)
self.count += 1
def dequeue(self):
if self.is_empty():
raise ValueError("Empty Queue Error")
self.moveStack1ToStack2()
return self.stack2.pop()
def peek(self):
if self.is_empty():
raise ValueError("Empty Queue Error")
self.moveStack1ToStack2()
return self.stack2.peek()
def moveStack1ToStack2(self):
if self.stack2.is_empty():
while not self.stack1.is_empty():
self.stack2.push(self.stack1.pop())
def is_empty(self):
return self.stack1.is_empty() and self.stack2.is_empty()
