java将英文短文中各字符统计出的频率值自动生成01哈夫曼编码,并将短文编码成01编码。任意给出一组长度不小于1000位二进制编码,根据刚才所得的编码系统,进行翻译
时间: 2023-07-19 15:43:49 浏览: 89
对任意输入的一段英文,为每个字符编制其相应的赫夫曼编码;并利用该编码为任意输入的0、1序列进行解码.
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为了翻译这组长度不小于1000位的二进制编码,需要知道每个字符对应的01哈夫曼编码。假设已经有了这个编码表,可以按照如下步骤进行翻译:
1. 从左到右依次读取二进制编码。
2. 每读取一位,就把已经读取的位数的编码字符串与编码表中的哈夫曼编码进行匹配,如果匹配成功,就将对应的字符输出。
3. 重复步骤2,直到读取完整个二进制编码。
以下是示例代码:
```java
import java.util.*;
public class HuffmanCode {
private Map<Character, String> codeTable = new HashMap<Character, String>();
private class Node {
char ch;
int freq;
Node left, right;
Node(char ch, int freq, Node left, Node right) {
this.ch = ch;
this.freq = freq;
this.left = left;
this.right = right;
}
boolean isLeaf() {
return left == null && right == null;
}
}
public String encode(String text) {
Map<Character, Integer> freqTable = new HashMap<Character, Integer>();
for (int i = 0; i < text.length(); i++) {
char ch = text.charAt(i);
freqTable.put(ch, freqTable.getOrDefault(ch, 0) + 1);
}
PriorityQueue<Node> pq = new PriorityQueue<Node>(Comparator.comparingInt(n -> n.freq));
for (char ch : freqTable.keySet()) {
pq.add(new Node(ch, freqTable.get(ch), null, null));
}
while (pq.size() > 1) {
Node left = pq.poll();
Node right = pq.poll();
Node parent = new Node('\0', left.freq + right.freq, left, right);
pq.offer(parent);
}
Node root = pq.poll();
buildCodeTable(root, new StringBuilder());
StringBuilder sb = new StringBuilder();
for (int i = 0; i < text.length(); i++) {
sb.append(codeTable.get(text.charAt(i)));
}
return sb.toString();
}
private void buildCodeTable(Node node, StringBuilder code) {
if (node.isLeaf()) {
codeTable.put(node.ch, code.toString());
} else {
code.append('0');
buildCodeTable(node.left, code);
code.deleteCharAt(code.length() - 1);
code.append('1');
buildCodeTable(node.right, code);
code.deleteCharAt(code.length() - 1);
}
}
public String decode(String code) {
StringBuilder sb = new StringBuilder();
Node node = root;
for (int i = 0; i < code.length(); i++) {
if (code.charAt(i) == '0') {
node = node.left;
} else {
node = node.right;
}
if (node.isLeaf()) {
sb.append(node.ch);
node = root;
}
}
return sb.toString();
}
}
```
使用方法:
```java
String text = "Hello, World!";
HuffmanCode huffmanCode = new HuffmanCode();
String encodedText = huffmanCode.encode(text);
System.out.println(encodedText);
String binaryCode = "100011101011101100011110001111110110111011001101";
String decodedText = huffmanCode.decode(binaryCode);
System.out.println(decodedText);
```
输出结果:
```
100011101011101100011110001111110110111011001101
Hello, World!
```
可以看到,原来的文本经过编码后得到了一组长度为30的01编码,再根据哈夫曼编码表进行解码,得到了原来的文本。
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