帮我用python实现lz78算法
时间: 2024-06-09 12:02:50 浏览: 4
好的,LZ78 是一种无损数据压缩算法,它是由Abraham Lempel 和 Jacob Ziv 于1978年提出的。该算法是一种基于字典编码的压缩算法。
以下是Python实现LZ78算法的示例代码:
```python
def compress_LZ78(text):
dictionary = {chr(i): i for i in range(256)}
curr_str = ""
result = []
for c in text:
if curr_str + c in dictionary:
curr_str += c
else:
result.append(dictionary[curr_str])
dictionary[curr_str + c] = len(dictionary)
curr_str = ""
if curr_str != "":
result.append(dictionary[curr_str])
return result
def decompress_LZ78(compressed_text):
dictionary = {i: chr(i) for i in range(256)}
curr_str = ""
result = []
for i in compressed_text:
if i in dictionary:
result.append(dictionary[i])
if curr_str != "":
dictionary[len(dictionary)] = curr_str + dictionary[i]
curr_str = dictionary[i]
else:
s = curr_str + curr_str
result.append(s)
dictionary[len(dictionary)] = s
curr_str = s
return ''.join(result)
```
这里我们定义了两个函数,`compress_LZ78` 和 `decompress_LZ78` 分别用于压缩和解压缩。你只需要调用这两个函数并传入需要处理的文本即可。
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