(self)
| 50 | |
| 51 | |
| 52 | def dequeue(self): |
| 53 | if self.isEmpty(): |
| 54 | return "there is no element in queue" |
| 55 | else: |
| 56 | firstElement = self.items[self.start] |
| 57 | start = self.start |
| 58 | if self.start ==self.top: |
| 59 | self.start=-1 |
| 60 | self.top=-1 |
| 61 | elif self.start+1==self.maxsize: |
| 62 | self.start=0 |
| 63 | else: |
| 64 | self.start+=1 |
| 65 | self.items[start]=None |
| 66 | return firstElement |
| 67 | |
| 68 | |
| 69 |