1 #!/usr/bin/env python
2
3 class QueueUnderflow(ValueError):
4 pass
5
6 class PrioQue(object):
7 def __init__(self, elems=[]):
8 #list can be change locally, so list it
9 self.elems = list(elems)
10 self.elems.sort(reverse=True)
11
12 def is_empty(self):
13 return self.elems == None
14
15 def peek(self):
16 if self.is_empty():
17 raise QueueUnderflow
18 return self.elems[-1]
19
20 def dequeue(self):
21 if self.is_empty():
22 raise QueueUnderflow
23 return self.elems.pop()
24
25 def enqueue(self, elem):
26 i = len(self.elems) - 1
27 while i>=0:
28 if self.elems[i] <= elem:
29 i -= 1
30 else:
31 break
32 self.elems.insert(i+1, elem)
33
34 if __name__ == '__main__':
35 pq = PrioQue(elems=[6,4,3,8,5,1,2,0,9])
36 print(pq.elems)
37 pq.enqueue(7)
38 print(pq.elems)
