class Trendtracker

$\{$

private:

vector trackedHashtags;

$//$ For the mandatory running times below:

$//$ n is the number of hashtags in the Trendtracker.

public:

$//$ Creates a new Trendtracker tracking no hashtags.

$//$

$//$ Must run in O$(1)$ time.

Trendtracker$()$;

$//$ Inserts a hashtag $($tweeted $0$ times$)$ into the Trendtracker.

$//$ If the hashtag already is in Trendtracker, does nothing.

$//$

$//$ Must run in O$($n$)$ time.

void insert$($string ht$)$;

$//$ Return the number of hashtags in the Trendtracker.

$//$

$//$ Must run in O$(1)$ time.

int size$()$;

$//$ Adds $1$ to the total number times a hashtag has been tweeted.

$//$ If the hashtag does not exist in TrendTracker, does nothing.

$//$

$//$ Must run in O$($n$)$ time.

void tweeted$($string ht$)$;

$//$ Returns the number of times a hashtag has been tweeted.

$//$ If the hashtag does not exist in Trendtracker, returns $-1.$

$//$

$//$ Must run in O$($n$)$ time.

int popularity$($string name$)$;

$//$ Returns a most$-$tweeted hashtag.

$//$ If the Trendtracker has no hashtags, returns $"".$

$//$

$//$ Must run in O$($n$)$ time.

string top$\_$trend$()$;

$//$ Fills the provided vector with the $3$ most$-$tweeted hashtags,

$//$ in order from most$-$tweeted to least$-$tweeted.

$//$

$//$ If there are fewer than $3$ hashtags, then the vector is filled

$//$ with all hashtags $($in most$-$tweeted to least$-$tweeted order$).$