LC.P676[实现一个魔法字典]

方法一：Trie

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class MagicDictionary {

    Trie node;

    public MagicDictionary() {
        node = new Trie();
    }

    public void buildDict(String[] dictionary) {
        for (String s : dictionary) node.insert(s);
    }

    public boolean search(String searchWord) {
        return node.query(searchWord, node, 0, false);
    }

    private static class Trie {
        Trie[] next;
        boolean isEnd;

        public Trie() {
            next = new Trie[26];
            isEnd = false;
        }

        public void insert(String word) {
            Trie node = this;
            for (int i = 0; i < word.length(); ++i) {
                char c = word.charAt(i);
                if (node.next[c - 'a'] == null) {
                    node.next[c - 'a'] = new Trie();
                }
                node = node.next[c - 'a'];
            }
            node.isEnd = true;
        }

        public boolean query(String word, Trie node, int pos, boolean modified) {
            if (pos == word.length()) return node.isEnd && modified;
            int idx = word.charAt(pos) - 'a';
            if (node.next[idx] != null) {
                if (query(word, node.next[idx], pos + 1, modified)) return true;
            }
            if (!modified) {
                for (int i = 0; i < 26; ++i) {
                    if (i != idx && node.next[i] != null) {
                        if (query(word, node.next[i], pos + 1, true)) return true;
                    }
                }
            }
            return false;
        }
    }
}

/**
 * Your MagicDictionary object will be instantiated and called as such:
 * MagicDictionary obj = new MagicDictionary();
 * obj.buildDict(dictionary);
 * boolean param_2 = obj.search(searchWord);
 */

方法二：暴力

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class MagicDictionary {

    String[] dictionary;

    public void buildDict(String[] dictionary) {
        this.dictionary = dictionary;
    }
    public boolean search(String searchWord) {
        for (String s : dictionary) {
            int cnt = 0;
            for (int i = 0; s.length() == searchWord.length() && i < s.length() && cnt <= 1; ++i) {
                if (s.charAt(i) != searchWord.charAt(i)) ++cnt;
            }
            if (cnt == 1) return true;
        }
        return false;
    }
}

/**
 * Your MagicDictionary object will be instantiated and called as such:
 * MagicDictionary obj = new MagicDictionary();
 * obj.buildDict(dictionary);
 * boolean param_2 = obj.search(searchWord);
 */