Suppose data is available for an on-line music distributor. This data includes: song title, artist performing the song, date song purchased, amount charged for the song. Using only the information available in the distributor's data (song title, artist performing, date purchased, amount charged), which of the following can be determined using database or spreadsheet software? a. The number of songs by a particular artist that were purchased on a given date.
b. The amount of money charged on the first day of any given month.
c. Whether the amount charged is the same for each song title.

Some of your friends have gotten into the burgeoning field of time-series data mining, in which one looks for patterns in sequences of events that occur over time. purchases at stock exchanges"what's being bought" are one source of data with a natural ordering in time. given a long sequence s of such events, your friends want an efficient way to detect certain "patterns" in them"for example, they may want to know if the four events buy yahoo, buy ebay, buy yahoo, buy oracle occur in this sequence s, in order but not necessarily consecutively. they begin with a collection of possible events (e.g., the possible transactions) and a sequence s of n of these events. a given event may occur multiple times in s (e.g., yahoo stock may be bought many times in a single sequence s). we will say that a sequence s is a subsequence of s if there is a way to delete certain of the events from s so that the remaining events, in order, are equal to the sequence s . so, for example, the sequence of four events above is a subsequence of the sequence buy amazon, buy yahoo, buy ebay, buy yahoo, buy yahoo, buy oracle their goal is to be able to dream up short sequences and quickly detect whether they are subsequences of s. so this is the problem they pose to you: give an algorithm that takes two sequences of events"s of length m and s of length n, each possibly containing an event more than once"and decides in time o(m + n) whether s is a subsequence of s.

Match the personality traits with their description

Consider the following code snippet: #ifndef cashregister_h#define cashregister_hconst double max_balance = 6000000.0; class cashregister{public: cashregister(); cashregister(double new_balance); void set_balance(double new_balance); double get_balance() const; private: double balance[12]; }; double get_monthly_balance(cashregister bk, int month); #endifwhich of the following is correct? a)the header file is correct as given.b)the definition of max_balance should be removed since header files should not contain constants.c)the definition of cashregister should be removed since header files should not contain class definitions.d)the body of the get_monthly_balance function should be added to the header file.