在英语中，我们有一个叫做 词根(root) 的概念，可以词根后面添加其他一些词组成另一个较长的单词——我们称这个词为 继承词(successor)。例如，词根an，跟随着单词 other(其他)，可以形成新的单词 another(另一个)。
现在，给定一个由许多词根组成的词典 dictionary 和一个用空格分隔单词形成的句子 sentence。你需要将句子中的所有继承词用词根替换掉。如果继承词有许多可以形成它的词根，则用最短的词根替换它。
你需要输出替换之后的句子。
示例 1：
输入：dictionary = ["cat","bat","rat"], sentence = "the cattle was rattled by the battery" 输出："the cat was rat by the bat"
示例 2：
输入：dictionary = ["a","b","c"], sentence = "aadsfasf absbs bbab cadsfafs" 输出："a a b c"
提示：
1 <= dictionary.length <= 10001 <= dictionary[i].length <= 100dictionary[i]仅由小写字母组成。1 <= sentence.length <= 10^6sentence仅由小写字母和空格组成。sentence中单词的总量在范围[1, 1000]内。sentence中每个单词的长度在范围[1, 1000]内。sentence中单词之间由一个空格隔开。sentence没有前导或尾随空格。
方法一：哈希表
方法二：前缀树
class Solution:
def replaceWords(self, dictionary: List[str], sentence: str) -> str:
s = set(dictionary)
words = sentence.split()
for i, word in enumerate(words):
for j in range(1, len(word) + 1):
if word[:j] in s:
words[i] = word[:j]
break
return ' '.join(words)class Trie:
def __init__(self):
self.children = [None] * 26
self.v = None
def insert(self, word):
node = self
for c in word:
idx = ord(c) - ord('a')
if node.children[idx] is None:
node.children[idx] = Trie()
node = node.children[idx]
node.v = word
def search(self, word):
node = self
for c in word:
idx = ord(c) - ord('a')
if node.children[idx] is None:
break
node = node.children[idx]
if node.v:
return node.v
return word
class Solution:
def replaceWords(self, dictionary: List[str], sentence: str) -> str:
trie = Trie()
for v in dictionary:
trie.insert(v)
return ' '.join(trie.search(v) for v in sentence.split())class Solution {
public String replaceWords(List<String> dictionary, String sentence) {
Set<String> s = new HashSet<>(dictionary);
String[] words = sentence.split(" ");
for (int i = 0; i < words.length; ++i) {
String word = words[i];
for (int j = 1; j <= word.length(); ++j) {
String t = word.substring(0, j);
if (s.contains(t)) {
words[i] = t;
break;
}
}
}
return String.join(" ", words);
}
}class Trie {
Trie[] children = new Trie[26];
String v;
void insert(String word) {
Trie node = this;
for (char c : word.toCharArray()) {
c -= 'a';
if (node.children[c] == null) {
node.children[c] = new Trie();
}
node = node.children[c];
}
node.v = word;
}
String search(String word) {
Trie node = this;
for (char c : word.toCharArray()) {
c -= 'a';
if (node.children[c] == null) {
return word;
}
node = node.children[c];
if (node.v != null) {
return node.v;
}
}
return word;
}
}
class Solution {
public String replaceWords(List<String> dictionary, String sentence) {
Trie trie = new Trie();
for (String v : dictionary) {
trie.insert(v);
}
List<String> ans = new ArrayList<>();
for (String v : sentence.split("\\s")) {
ans.add(trie.search(v));
}
return String.join(" ", ans);
}
}class Solution {
public:
string replaceWords(vector<string>& dictionary, string sentence) {
unordered_set<string> s(dictionary.begin(), dictionary.end());
istringstream is(sentence);
vector<string> words;
string ss;
while (is >> ss) words.push_back(ss);
for (int i = 0; i < words.size(); ++i) {
string word = words[i];
for (int j = 1; j <= word.size(); ++j) {
string t = word.substr(0, j);
if (s.count(t)) {
words[i] = t;
break;
}
}
}
string ans = "";
for (string& word : words) ans += word + " ";
ans.pop_back();
return ans;
}
};class Trie {
public:
vector<Trie*> children;
string v;
Trie() : children(26), v("") {}
void insert(string word) {
Trie* node = this;
for (char c : word)
{
c -= 'a';
if (!node->children[c]) node->children[c] = new Trie();
node = node->children[c];
}
node->v = word;
}
string search(string word) {
Trie* node = this;
for (char c : word)
{
c -= 'a';
if (!node->children[c]) break;
node = node->children[c];
if (node->v != "") return node->v;
}
return word;
}
};
class Solution {
public:
string replaceWords(vector<string>& dictionary, string sentence) {
Trie* trie = new Trie();
for (auto& v : dictionary) trie->insert(v);
string ans = "";
istringstream is(sentence);
vector<string> ss;
string s;
while (is >> s) ss.push_back(s);
for (auto word : ss) ans += trie->search(word) + " ";
ans.pop_back();
return ans;
}
};func replaceWords(dictionary []string, sentence string) string {
s := map[string]bool{}
for _, v := range dictionary {
s[v] = true
}
words := strings.Split(sentence, " ")
for i, word := range words {
for j := 1; j <= len(word); j++ {
t := word[:j]
if s[t] {
words[i] = t
break
}
}
}
return strings.Join(words, " ")
}type Trie struct {
children [26]*Trie
v string
}
func newTrie() *Trie {
return &Trie{}
}
func (this *Trie) insert(word string) {
node := this
for _, c := range word {
c -= 'a'
if node.children[c] == nil {
node.children[c] = newTrie()
}
node = node.children[c]
}
node.v = word
}
func (this *Trie) search(word string) string {
node := this
for _, c := range word {
c -= 'a'
if node.children[c] == nil {
break
}
node = node.children[c]
if node.v != "" {
return node.v
}
}
return word
}
func replaceWords(dictionary []string, sentence string) string {
trie := newTrie()
for _, v := range dictionary {
trie.insert(v)
}
var ans []string
for _, v := range strings.Split(sentence, " ") {
ans = append(ans, trie.search(v))
}
return strings.Join(ans, " ")
}