adding in some C++ solutions

C++/05. Inheritance/04. Magic Spells.cpp

@@ -0,0 +1,127 @@
+// Problem: https://www.hackerrank.com/challenges/magic-spells/problem
+// Score: 40
+
+// PROVIDED CODE BY HACKERRANK
+#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 = "";
+
+// SOLUTION START
+void counterspell(Spell *spell) {
+	auto *x0 = dynamic_cast<Fireball*>(spell);
+	if (x0) { x0->revealFirepower(); return ;}
+	auto *x1 = dynamic_cast<Frostbite*>(spell);
+	if (x1) {x1->revealFrostpower(); return ;}
+	auto *x2 = dynamic_cast<Thunderstorm*>(spell);
+	if (x2) {x2->revealThunderpower(); return ; }
+	auto *x3 = dynamic_cast<Waterbolt*>(spell);
+	if (x3) {x3->revealWaterpower(); return; }
+
+	string a = spell->revealScrollName(), b = SpellJournal::read();
+	int m = a.size(), n = b.size();
+	vector<vector<int> > s(m+1, vector<int>(n+1, 0));
+	for (int i = 0; i < m; i++) {
+		for (int j = 0; j < n; j++)
+			s[i+1][j+1] = max(s[i][j]+(a[i]==b[j]), max(s[i+1][j], s[i][j+1]));
+	}
+	cout << s[m][n] << '\n';
+
+}
+// SOLUTION END
+
+// PROVIDED CODE BY HACKERRANK
+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;
+}