648. Replace Words
class TrieNode {
public:
bool is_end;
vector<TrieNode*> children = vector<TrieNode*>(26, nullptr);
TrieNode() {
is_end = false; }
};
class Solution {
public:
TrieNode* root = new TrieNode();
TrieNode* p;
void insert(string word) {
p = root;
for(int ii = 0; ii < word.size(); ii++) {
if(!p->children[word[ii] - 'a']) p->children[word[ii] - 'a'] = new TrieNode();
p = p->children[word[ii] - 'a'];
}
p->is_end = true;
}
string replaceWords(vector<string>& dictionary, string sentence) {
for(auto &word : dictionary) insert(word);
string result = "";
bool tag = false;
int start = 0;
p = root;
for(int ii = 0; ii < sentence.size(); ii++) {
if(sentence[ii] == ' ' || ii == sentence.size() - 1) {
result += sentence.substr(start, ii - start + 1);
start = ii+1;
p = root;
}
else {
if(p->children[sentence[ii] - 'a']) {
p = p->children[sentence[ii] - 'a'];
if(p->is_end) {
result += sentence.substr(start, ii - start + 1);
while(ii < sentence.size() && sentence[ii] != ' ') ii++;
start = ii+1;
if(start < sentence.size()) result += ' ';
p = root;
}
}
else {
while(ii < sentence.size() && sentence[ii] != ' ') ii++;
result += sentence.substr(start, ii - start + 1);
start = ii+1;
p = root;
}
}
}
return result;
}
};