Added isPrime

Algorithms.hpp

@@ -34,6 +34,9 @@ namespace mee{
 
 //A list of functions in the file
 //Also works as prototypes with general information
+//This function determines whether the number passed into it is a prime
+template <class T>
+bool isPrime(T num);
 //This is a function that returns all the primes <= goalNumber and returns a vector with those prime numbers
 template <class T>
 std::vector<T> getPrimes(T goalNumber);
@@ -103,6 +106,7 @@ std::vector<T> getPrimes(T goalNumber){
 	else{
 		primes.push_back(2);
 	}
+
 	//We can now start at 3 and skip all of the even numbers
 	for(T possiblePrime = 3;possiblePrime <= goalNumber;possiblePrime += 2){
 		//Step through every element in the current primes. If you don't find anything that divides it, it must be a prime itself
@@ -122,6 +126,7 @@ std::vector<T> getPrimes(T goalNumber){
 			foundFactor = false;
 		}
 	}
+
 	std::sort(primes.begin(), primes.end());
 	return primes;
 }
@@ -168,6 +173,23 @@ std::vector<T> getNumPrimes(T numberOfPrimes){
 	return primes;
 }
 
+//This function determines whether the number passed into it is a prime
+template <class T>
+bool isPrime(T num){
+	if(num <= 3){
+		return num > 1;
+	}
+	else if(((num % 2) == 0) || ((num % 3) == 0)){
+		return false;
+	}
+	for(T cnt = 5;(cnt * cnt) <= num;cnt += 6){
+		if(((num % cnt) == 0) || ((num % (cnt + 2)) == 0)){
+			return false;
+		}
+	}
+	return true;
+}
+
 //This function returns all prime factors of a number
 template <class T>
 std::vector<T> getFactors(T goalNumber){