# !/usr/bin/env python

# -*- coding: utf-8 -*-

__author__ = 'MrHero'

"""

串的顺序存储结构有两种: 非紧缩格式, 紧缩格式

非紧缩格式: 每个单元只存一个字符

紧缩格式: 每个单元放多个字符

"""

class SqString(object):

def __init__(self, size=0):

self.data = list(None for _ in range(size))

self.max_size = size

self.length = 0

def assign(self, str):

# 将字符串常量赋值为串s, 即生成一个值等于cstr的串

for i, item in enumerate(str):

self.data[i] = item

self.length += 1

def show_str(self):

# 将字符串输出

if self.length == 0:

raise ValueError("SqString is empty!")

for i, item in enumerate(self.data):

if item is None:

break

else:

print item,

print ""

def copy(self, sqrstr):

# 将该串复制给 sqrstr

if self.length == 0:

sqrstr.length = 0

sqrstr.max_size = self.max_size

sqrstr.data = list(None for _ in range(self.max_size))

else:

sqrstr.length = self.length

sqrstr.max_size = self.max_size

sqrstr.data = list(None for _ in range(self.max_size))

for i, item in enumerate(self.data):

sqrstr.data[i] = item

def equal(self, sqstr):

# 判断串相等: 若两个串s 与 t 相等返回 True, 否则返回 False

if self.length != sqstr.length:

return False

for i in range(self.length):

if self.data[i] != sqstr.data[i]:

return False

return True

def get_length(self):

return self.length

def concat(self, sqstr):

# 串连接

result = SqString()

result.length = self.length + sqstr.length

result.data = list(None for _ in range(self.max_size + sqstr.max_size))

# 先将自身复制到result中

for i in enumerate(self.data):

result.data[i] = self.data[i]

# 再将sqstr复制到result中

for i in enumerate(sqstr.data):

result.data[self.length + i] = sqstr.data[i]

return result

def sub_str(self, i, j):

# 求字串: 返回串s 中从第 i(1<= i <= self.length) 个字符开始，由连续

# j个字符组成的子串

# 返回新串

if i <= 0 or i > self.length or i + j - 1 > self.length:

raise IndexError("Index error!")

result = SqString(j)

for k, item in enumerate(self.data[i-1:i+j-1]):

result.data[k] = item

result.length += 1

return result

def ins_str(self, i, sqstr):

# 将串 sqstr 插入到 该串的第i 个字符中，即将 sqstr 的第一个字符作为s1的第i个字符，

# 并返回返回产生的新串

if i <= 0 or i > self.length:

raise IndexError("Index is out of range!")

result = SqString(self.max_size + sqstr.max_size)

#将 self.data[0:i-2] 复制到result中

for k, item in enumerate(self.data[0:i-1]):

result.data[k] = item

result.length += 1

#将 sqstr 复制到result中

# len2 = result.length

for k, item2 in enumerate(sqstr.data):

if item2 is not None:

result.data[i - 1 + k] = item2

result.length += 1

else:

break

#将 self.data[i-1:] 复制到result中

# len3 = result.length

for k, item3 in enumerate(self.data[i-1:]):

if item3 is not None:

result.data[i - 1 + sqstr.length + k] = item3

result.length += 1

else:

break

return result

def del_str(self, i, j):

# 从串s 中删除第 i (1<= i <= self.length) 个字符开始，长度为j的字串

# 并返回产生的新串

# 参数不正确时返回一个空串

if i <= 0 or i > self.length or i + j - 1 > self.length:

raise IndexError("Index is out of range")

result = SqString(self.length - j)

for k, item in enumerate(self.data[0:i]):

result.data[k] = item

result.length += 1

for k, item in enumerate(self.data[i + j - 1:]):

if item is not None:

result.data[i - 1 + k] = item

result.length += 1

else:

break

return result

def rep_str(self, i, j, sqstr):

# 在串self中，将第i(1<= i <= self.length)个字符开始的j个字符构成的子串用串t替换，

# 并返回产生的新串。

# 参数不正确是返回一个空串。

if i <= 0 or i > self.length or i + j - 1 > self.length:

raise IndexError("Index is out of range")

result = SqString(self.length - j + sqstr.length)

for k, item in enumerate(self.data[0:i]):

result.data[k] = item

result.length += 1

for k, item in enumerate(sqstr.data):

if item is not None:

result.data[i - 1 + k] = item

result.length += 1

for k, item in enumerate(self.data[i + j - 1:]):

if item is not None:

result.data[i - 1 + sqstr.length + k] = item

result.length += 1

return result

if __name__ == '__main__':

sqstr = SqString(30)

ss = "abcdefghijklmnopqlstuvwxyz"

sqstr.assign(ss)

sqstr.show_str()

sqtest = SqString()

sqstr.copy(sqtest)

sqtest.show_str()

a = sqstr.equal(sqtest)

print a

result = sqstr.sub_str(3, 5)

result.show_str()

sss = "123"

test1 = SqString(5)

test1.assign(sss)

result2 = sqstr.ins_str(3, test1)

result2.show_str()

result3 = result2.del_str(5, 6)

result3.show_str()

result4 = result3.rep_str(5, 4, test1)

result4.show_str()