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say hello world with C++ - Solution in Hacker Rank - hackerranksolutions8

  Objective This is a simple challenge to help you practice printing to  stdout . You may also want to complete  Solve Me First  in C++ before attempting this challenge. We’re starting out by printing the most famous computing phrase of all time! In the editor below, use either  printf  or  cout  to print the string  Hello ,World!  to  stdout . The more popular command form is  cout . It has the following basic form: cout<<value_to_print<<value_to_print; Any number of values can be printed using one command as shown. The  printf  command comes from C language. It accepts an optional format specification and a list of variables. Two examples for printing a string are: printf("%s", string);   printf(string); Note that neither method adds a newline. It only prints what you tell it to. Output Format Print   Hello ,World!   to stdout. Sample Output Hello, World! Solution:- //Say Hello, ...

Magic Spells in C++ – Solution in Hacker Rank - hackerranksolutions8

 

Problem

You are battling a powerful dark wizard. He casts his spells from a distance, giving you only a few seconds to react and conjure your counterspells. For a counterspell to be effective, you must first identify what kind of spell you are dealing with.
The wizard uses scrolls to conjure his spells, and sometimes he uses some of his generic spells that restore his stamina. In that case, you will be able to extract the name of the scroll from the spell. Then you need to find out how similar this new spell is to the spell formulas written in your spell journal.
Spend some time reviewing the locked code in your editor, and complete the body of the counterspell function.

Check Dynamic cast to get an idea of how to solve this challenge.


Input Format :

The wizard will read t scrolls, which are hidden from you.
Every time he casts a spell, it’s passed as an argument to your counterspell function.

Constraints :

  • 1 <= t <= 100
  • 1 <= |s| <= 1000, where s is a scroll name.
  • Each scroll name s, consists of uppercase and lowercase.

Output Format :

After identifying the given spell, print its name and power.
If it is a generic spell, find a subsequence of letters that are contained in both the spell name and your spell journal. Among all such subsequences, find and print the length of the longest one on a new line.


Sample Input :

3
fire 5
AquaVitae 999 AruTaVae
frost 7

Sample Output :

Fireball: 5
6
Frostbite: 7

Explanation :

Fireball and Frostbite are common spell types.
AquaVitae is not, and when you compare it with AruTaVae in your spell journal, you get a sequence: AuaVae


Solution :

// Magic Spells in C++ - Hacker Rank Solution
#include <iostream>
#include <vector>
#include <string>
using namespace std;

class Spell 
{ 
    private:
        string scrollName;
    public:
        Spell(): scrollName("") { }
        Spell(string name): scrollName(name) { }
        virtual ~Spell() { }
        string revealScrollName() 
        {
            return scrollName;
        }
};

class Fireball : public Spell 
{ 
    private: int power;
    public:
        Fireball(int power): power(power) { }
        void revealFirepower()
        {
            cout << "Fireball: " << power << endl;
        }
};

class Frostbite : public Spell {
    private: int power;
    public:
        Frostbite(int power): power(power) { }
        void revealFrostpower(){
            cout << "Frostbite: " << power << endl;
        }
};

class Thunderstorm : public Spell 
{ 
    private: int power;
    public:
        Thunderstorm(int power): power(power) { }
        void revealThunderpower()
        {
            cout << "Thunderstorm: " << power << endl;
        }
};

class Waterbolt : public Spell 
{ 
    private: int power;
    public:
        Waterbolt(int power): power(power) { }
        void revealWaterpower()
        {
            cout << "Waterbolt: " << power << endl;
        }
};

class SpellJournal 
{
    public:
        static string journal;
        static string read() 
        {
            return journal;
        }
}; 
string SpellJournal::journal = "";

void counterspell(Spell *spell) 
{
/* Magic Spells in C++ - Hacker Rank Solution START */
/* Enter your code here. Read input from STDIN. Print output to STDOUT */
    if (Fireball *s = dynamic_cast<Fireball *>(spell)) 
    {
        s->revealFirepower();
    } 
    else if (Frostbite *s = dynamic_cast<Frostbite *>(spell)) 
    {
        s->revealFrostpower();
    } 
    else if (Thunderstorm *s = dynamic_cast<Thunderstorm *>(spell)) 
    {
        s->revealThunderpower();
    } 
    else if (Waterbolt *s = dynamic_cast<Waterbolt *>(spell)) 
    {
        s->revealWaterpower();
    } 
    else 
    {
        string scroll_name = spell->revealScrollName();
        string journal = SpellJournal::read();
        size_t s_size = scroll_name.size();
        size_t j_size = journal.size();

        if (s_size == 1 && j_size == 1 && scroll_name == journal) 
        {
            cout << 1 << endl;
        } 
        else 
        {
            vector<vector<size_t>> lcs_table(s_size + 1, vector<size_t>(j_size + 1));

            for (size_t i = 1; i <= s_size; ++i) 
            {
                for (size_t j = 1; j <= j_size; ++j) 
                {
                    if (scroll_name[i - 1] == journal[j - 1]) 
                    {
                        lcs_table[i][j] = lcs_table[i - 1][j - 1] + 1;
                    } 
                    else 
                    {
                        lcs_table[i][j] = max(lcs_table[i][j - 1], lcs_table[i - 1][j]);
                    } 
                }
            }
          cout << lcs_table[s_size][j_size] << endl;
        }
    }
/* Magic Spells in C++ - Hacker Rank Solution END */

}

class Wizard 
{
    public:
        Spell *cast() 
        {
            Spell *spell;
            string s; cin >> s;
            int power; cin >> power;
            if(s == "fire") 
            {
                spell = new Fireball(power);
            }
            else if(s == "frost") 
            {
                spell = new Frostbite(power);
            }
            else if(s == "water") 
            {
                spell = new Waterbolt(power);
            }
            else if(s == "thunder") 
            {
                spell = new Thunderstorm(power);
            } 
            else 
            {
                spell = new Spell(s);
                cin >> SpellJournal::journal;
            }
            return spell;
        }
};

int main() 
{
    int T;
    cin >> T;
    Wizard Arawn;
    while(T--) 
    {
        Spell *spell = Arawn.cast();
        counterspell(spell);
    }
    return 0;
}

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