两个栈实现队列
# 栈实现对列 lin=[] lout=[] def length(): return len(lin)+len(lout) def linepush(k): lin.append(k) def linepop(): if not length(): print("empty") else: if not lout: while(lin): num=lin.pop() lout.append(num) return lout.pop() def front(): if not length(): print("empty") else: if not lout: while(lin): num=lin.pop() lout.append(num) return lout[-1] def back(): if not length(): print("empty") else: if not lin: while(lout): num=lout.pop() lin.append(num) return lin[-1]
一个栈用来负责push操作,一个栈负责pop操作。