python 数据结构之顺序列表的实现
算法简要:
追加直接往列表后面添加元素,插入是将插入位置后的元素全部往后面移动一个位置,然后再将这个元素放到指定的位置,将长度加1删除是将该位置后面的元素往前移动,
覆盖该元素,然后再将长度减1
#!/usr/bin/python # -*- coding: utf-8 -*- class SeqList(object): def __init__(self,maxsize): self.maxsize = maxsize self.data = range(maxsize) self.last = len(self.data) -1 def __getitem__(self, key): if self.is_empty(): print 'seqlist is empty' return elif key<0 or key>self.last: print 'the given key is Error' return else: return self.data[key] def __setitem__(self, key, value): if self.is_empty(): print 'seqlist is empty' return elif key<0 or key>self.last: print 'the given key is Error' return else: self.data[key] = value def __len__(self): length = self.last + 1 return length def getlength(self): return self.last+1 def clear(self): self.data = [] def is_empty(self): if self.last == -1: return True else: return False def is_full(self): if self.last == self.maxsize-1: return True else: return False def getelem(self,index): if self.is_empty(): print 'seqlist is empty' return elif index<0 or index>self.last: print 'position is error' else: return self.data[index] def getindex(self,elem): if self.is_empty(): print 'seqlst is empty' return else: for i in range(self.last): if self.data[i]==elem: return i def append(self,elem): if self.is_empty(): print 'seqlist is empty' return else: self.last +=1 self.data = self.data + [elem] def insert(self,index,elem): if self.is_empty(): print 'seqlist is empty' return elif index<0 or index> self.last+1: print 'postion is error' return elif index == self.last+1: self.last+=1 self.data = self.data + [elem] else: self.data += [elem] if index ==0: for i in self.data[self.last::-1]: self.data[i+1] = self.data[i] else: for i in self.data[self.last:index-1:-1]: self.data[i+1] = self.data[i] self.data[index] = elem self.last+=1 #print self.data def delete(self,index): if self.is_empty(): print 'seqlist is empty' return elif index<0 or index> self.last+1: print 'postion is error' return elif index == self.last+1: self.last -= 1 self.data =self.data[:-1] else: for i in self.data[:-1]: if i >= index: self.data[i] = self.data[i+1] else: pass self.data = self.data[:-1] self.last -= 1 sl = SeqList(5) print sl.data sl.append(5) print sl.data sl.insert(6,10) print sl.data sl.delete(5) print sl.data
说明:其实python中得list 本身是支持该种数据结构的,可以直接使用。