【Python】【数据结构】【线性表的实现】

一、线性表类的定义

class Sqlist:
    capacity=0
    size=0
    newcapacity=0
    def __init__(self):
        self.initcapacity=5;
        self.capacity=self.initcapacity
        self.data=[None]*self.capacity
        self.size=0

    def resize(self,newcapacity):
        assert newcapacity>=0
        olddata=self.data
        self.data=[None]*self.newcapacity
        self.capacity=newcapacity
        for i in range(self.size):
            self.data[i]=olddata[i]

    def CreateList(self,a):
        for i in range(0,len(a)):
            if self.size==self.capacity:
                self.resize(2*self.size);
            self.data[self.size]=a[i]
            self.size+=1

    def Add(self,e):
        if self.size==self.capacity:
            self.resize(2*self.size)
        self.data[self.size]=e
        self.size+=1

    def getsize(self):
        return self.size

    def __getitem__(self,i):
        assert 0<=iself.size):
            return -1;
        else:
            return i;

    def Insert(self,i,e):
        assert 0<=i<=self.size
        if self.size==self.capacity:
            self.resize(2*self.size)
        for j in range(self.size,i-1,-1):
            self.data[j]=self.data[j-1]
        self.data[i]=e
        self.size+=1

    def Delete(self,i):
        assert 0<=i<=self.size-1
        for j in range(i,self.size-1):
            self.data[j]=self.data[j+1]
        self.size-=1
        if self.capacity>self.initcapacity and self.size<=self.capacity/4:
            self.resize(self.capacity//2)

    def display(self):
        for i in range(self.size):
            print(self.data[i],end=' ')
        print()

二、线性表类的测试代码

if __name__=='__main__':
    L=Sqlist()
    for i in range(1,6) :
        L.Add(i)
    print ("L: ",end=' '),L.display()
    print("序号为2的元素=%d"%(L[2]))
    print("设置序号为2的元素为8")
    L[2]=8
    print("序号为2的元素=%d" %(L[2]))
    n=L.getsize()
    print ("size=%d" %(n))
    for i in range(0,n):
        print("删除%d序号的元素"%(0))
        L.Delete(0)

    print("L:",end=" "),L.display()
    print ("size=%d" %(L.getsize ()))