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class Solution {
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 public:
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  vector<string> spellchecker(vector<string> &wordlist, vector<string> &queries) {
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    unordered_map<string, vector<int>> umap;
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    // step 1: add info in umap;
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    for (int curr = 0; curr < wordlist.size(); curr++) {
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      // case 1: add same;
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      umap[wordlist[curr]].push_back({curr});
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      // notice that the lowercase may appear;
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      // case 2: add lowercase;
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      string tmp = wordlist[curr];
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      transform(tmp.begin(), tmp.end(), tmp.begin(), ::tolower);
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      if (umap.find(tmp) == umap.end() && tmp != wordlist[curr]) umap[tmp].push_back({curr});
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      // case 3: add vowel errors;
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      // convert aeiou to _;
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      for (int c_index = 0; c_index < tmp.size(); c_index++) {
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        char c = tmp[c_index];
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        if (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u') tmp[c_index] = '_';
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      }
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      if (umap.find(tmp) == umap.end()) umap[tmp].push_back({curr});
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    }
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    // step 2: convert queries;
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    for (int curr = 0; curr < queries.size(); curr++) {
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      string tmp = queries[curr];
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      transform(tmp.begin(), tmp.end(), tmp.begin(), ::tolower);
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      // case 1: check same;
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      if (umap.find(queries[curr]) != umap.end()) {
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        queries[curr] = (umap[queries[curr]].size() == 1) ? wordlist[umap[queries[curr]][0]]
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                                                          : wordlist[umap[queries[curr]][1]];
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        continue;
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      }
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      // case 2: check lowercase;
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      if (umap.find(tmp) != umap.end() && tmp != queries[curr]) {
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        queries[curr] = wordlist[umap[tmp][0]];
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        continue;
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      }
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      // case 3: check vowel errors;
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      // convert aeiou to _;
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      for (int c_index = 0; c_index < tmp.size(); c_index++) {
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        char c = tmp[c_index];
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        if (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u') tmp[c_index] = '_';
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      }
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      if (umap.find(tmp) != umap.end()) {
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        queries[curr] = wordlist[umap[tmp][0]];
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        continue;
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      }
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      // case 4: not found;
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      queries[curr] = "";
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    }
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    return queries;
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  }
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};
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// 1. When the query exactly matches a word in the wordlist (case-sensitive),
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// you should return the same word back.
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// 2. When the query matches a word up to capitlization, you should return the
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// first such match in the wordlist.
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// 3. When the query matches a word up to vowel errors, you should return the
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// first such match in the wordlist.
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// 4. If the query has no matches in the wordlist, you should return the empty
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// string.