find an word in vector cocos2d-x

Question

I have an vector word_list, and i want to find an word in word_list. I use function

bool Mylayer::existWord(vector<string> word_list, string word)
{ 
    if (std::lower_bound(word_list.begin(), word_list.end(), word) != word_list.end())
    {
        return true;
    }
    return false;
}

but it find not exactly. Can some one tell me why ?

If you're trying to find an exact word, perhaps you should use `std::find`. — Bart van Nierop, Jul 29 '14 at 08:13
Why do you use member functions that act only on parameters? C++ allows non-member functions — Mircea Ispas, Jul 29 '14 at 08:55

Jarod42 · Answer 1 · 2014-07-29T08:57:11.510

7

Your method should look like:

bool Mylayer::existWord(
    const std::vector<std::string>& words,
    const std::string& word) const
{ 
    return std::find(words.begin(), words.end(), word) != words.end();
}

If your vector is sorted, you may use std::binary_search:

bool Mylayer::existWord(
    const std::vector<std::string>& words,
    const std::string& word) const
{ 
    assert(std::is_sorted(words.begin(), words.end())); // debug check
    return std::binary_search(words.begin(), words.end(), word);
}

If your collection is sorted without duplicate, you may use a std::set<std::string> and your method becomes:

bool Mylayer::existWord(
    const std::set<std::string>& words,
    const std::string& word) const
{ 
    return words.count(word) != 0;
}

edited Jul 29 '14 at 08:57

answered Jul 29 '14 at 08:49

Jarod42

203,559
14
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i have a question: does Find function distinguish uppercase and lowercase ? – Mr Vy Jul 29 '14 at 09:15
@MrVy: as `std::string`, so yes. An easy way to manage that is to *lower case* all strings (see [stl-string-to-lower-case](http://stackoverflow.com/questions/313970/stl-string-to-lower-case) for how to do that). An other way is to use `find_if` with a predicate. – Jarod42 Jul 29 '14 at 09:26

Niraj · Answer 2 · 2014-07-30T17:12:43.750

-1

you may try using find

ideone link: http://ideone.com/bgFZwU

bool existWord(vector<string> word_list, string word) {
    vector<string>:: iterator it;

    it= find(word_list.begin(), word_list.end(), word);
    if(it== word_list.end()) {
        return 0;
    } else {
        return 1;
    }
}

edited Jul 30 '14 at 17:12

answered Jul 29 '14 at 08:51

Niraj

477
6
16

find an word in vector cocos2d-x

2 Answers2