利用Trie树，来查找单词出现的次数

来源：互联网发布：司马懿和诸葛亮知乎编辑：程序博客网时间：2024/04/29 03:48

Trie节点

class TrieNode {    TrieNode nodes[];    boolean isSentence; //称为一个句子的话仍然可能会有子节点    int count; //表示当前节点实际上代表了多少个相同的单词    public TrieNode() {        nodes = new TrieNode[26]; //26个英文字母        isSentence = false;        count = 0;    }}

构造Trie树，以及查找节点

//单论小写字母void buildTrie(String str, TrieNode root) {    if (root == null)        return;    TrieNode curr = root;    char[] arr = str.toCharArray();    for (int i = 0; i < arr.length; ++i) {        if (curr.nodes[arr[i] - 'a'] == null) {            curr.nodes[arr[i] - 'a'] = new TrieNode();        }        curr = curr.nodes[arr[i] - 'a'];        if (i == arr.length - 1) {            curr.isSentence = true;            curr.count++;        }    }}int findStr(String str, TrieNode root) {    if (root == null)        return 0;    TrieNode curr = root;    char arr[] = str.toCharArray();    for (int i = 0; i < arr.length; ++i) {        if (curr.nodes[arr[i] - 'a'] == null)            return 0;        curr = curr.nodes[arr[i] - 'a'];        if (arr.length - 1 == i && curr.isSentence) {            return curr.count;        }    }    return 0;}

测试一下：

public static void main(String[] args) {    print p = new print();    TrieNode node = new TrieNode();    p.buildTrie("wangcheng", node);    p.buildTrie("abc", node);    p.buildTrie("abc", node);    p.buildTrie("hello", node);    p.buildTrie("hello", node);    int a = p.findStr("wangcheng", node);    System.out.println(a);}

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