Python中顺序表原理与实现方法详解

  /* This over-allocates proportional to the list size, making room
   * for additional growth. The over-allocation is mild, but is
   * enough to give linear-time amortized behavior over a long
   * sequence of appends() in the presence of a poorly-performing
   * system realloc().
   * The growth pattern is: 0, 4, 8, 16, 25, 35, 46, 58, 72, 88, ...
   */
  new_allocated = (newsize >> 3) + (newsize < 9 ? 3 : 6);
  /* check for integer overflow */
  if (new_allocated > PY_SIZE_MAX - newsize) {
    PyErr_NoMemory();
    return -1;
  } else {
    new_allocated += newsize;
  }

class shunxubiao:
  def __init__(self,length):#length表示顺序表的长度，决定此顺序表最多存储多少元素
    self.length=length
    self.data=[] #data表示顺序表内容
    self.biao=-1 #元素下标
  def weikong(self):#判断 这个顺序表是否是空的
    if self.biao==-1:
      return True
    else:
      return False
  def mande(self):#判断此顺序表是否是满的
    if self.biao+1==self.length:
      return True
    else:
      return False
  def qingkong(self):
    if not self.weikong():
      self.data=[]
      self.biao=-1
  def geshu(self):
    return self.biao+1
  def chazhao(self,x):#知道下标查找元素
    return self.data[x]
  def chazhao1(self,x):#知道元素查找下标
    if self.weikong():
      print('表为空')
      return -1
    for i in range(self.biao+1):
      if self.data[i]==x:
       return i
       break
       print('查找的元素不存在')
  def biaoweijia(self,x): #给顺序表表尾加一个元素
    if self.mande():
      print('biaoyiman')
    else:
     self.data.append(x)
    self.biao+=1
  def charu(self,index,x):#想顺序表的index位置插入x元素
    if self.mande():
      print('biayiman')
    elif index<0 or index>self.biao-1:
      print('bunengcharu')
    else:
      for i in range(self.biao,index-1):
        self.data[i+1]=self.data[i]
        self.data[index-1]=x
      self.biao+=1
  def shanchu(self,x):#删除指定元素x
    if self.weikong():#判断是不是空表
      print('kongde,bunengshanchu')
    index=-1#用index来找x的位置
    for i in (self.data):
      index+=1
      if i == x:
        break
    for i in range(index,self.biao-1):#把x元素之后的元素都向前推进一格
      self.data[i]=self.data[i+1]
    self.biao-=1
c=shunxubiao(6)
c.data=[2,4,5,6]
c.biao=3
c.weikong()
print(c.chazhao(2))#知道尾标2查找元素
print(c.chazhao1(4))#知道元素查找尾标
c.biaoweijia(7)#给表尾加元素
print(c.data)
print(c.biao)
c.charu(3,9)
print(c.data)
print(c.biao)
c.shanchu(7)
print(c.data)
print(c.biao)