def test_stack(self):
stack = Stack()
for i in [23, 4, 2, 56]:
stack.push(i)
self.assertEqual(stack.size(), 4)
self.assertEqual(stack.peek(), 56)
self.assertEqual(stack.pop(), 56)
stack.pop()
stack.pop()
stack.pop()
self.assertEqual(stack.size(), 0)
self.assertRaises(RuntimeError, stack.pop)
class Queue:
def __init__(self):
self.push_queue = Stack()
self.pop_queue = Stack()
def is_empty(self):
return self.pop_queue.is_empty() and self.push_queue.is_empty()
def enqueue(self, data):
self.push_queue.push(data)
def dequeue(self):
if self.is_empty():
raise Exception('Can\'t dequeue. Queue is empty')
if self.pop_queue.is_empty():
while (not self.push_queue.is_empty()):
self.push_queue.push(self.push_queue.pop())
return self.pop_queue.pop()
def size(self):
return self.push_queue.size() + self.pop_queue.size()
def check_balanced(expr):
opening = '([{'
closing = ')]}'
opening_d = {opening[i] : closing[i] for i in range(len(opening))}
closing_d = {closing[i] : opening[i] for i in range(len(opening))}
s = Stack()
for i, c in enumerate(expr):
if c in opening_d:
s.push(c)
if c in closing_d:
if not s.is_empty() and opening_d[s.peek()] == c:
s.pop()
else:
print('parenthèse fermante en trop au caractère', i+1)
return False
return s.size() == 0