Merge pull request zapellass123#460 from mishracode11/patch-1

Super_Prime_Number.cpp

Author: zapellass123

Super_Prime_Number.cpp

@@ -0,0 +1,56 @@
+// C++ program to print super primes less than or equal to n.
+#include <bits/stdc++.h>
+using namespace std;
+
+// Generate all prime numbers less than n.
+bool SieveOfEratosthenes(int n, bool isPrime[])
+{
+	// Initialize all entries of boolean array as true. A
+	// value in isPrime[i] will finally be false if i is Not
+	// a prime, else true bool isPrime[n+1];
+	isPrime[0] = isPrime[1] = false;
+	for (int i = 2; i <= n; i++)
+		isPrime[i] = true;
+
+	for (int p = 2; p * p <= n; p++) {
+		// If isPrime[p] is not changed, then it is a prime
+		if (isPrime[p] == true) {
+			// Update all multiples of p
+			for (int i = p * 2; i <= n; i += p)
+				isPrime[i] = false;
+		}
+	}
+}
+
+// Prints all super primes less than or equal to n.
+void superPrimes(int n)
+{
+	// Generating primes using Sieve
+	bool isPrime[n + 1];
+	SieveOfEratosthenes(n, isPrime);
+
+	// Storing all the primes generated in a an array
+	// primes[]
+	int primes[n + 1], j = 0;
+	for (int p = 2; p <= n; p++)
+		if (isPrime[p])
+			primes[j++] = p;
+
+	// Printing all those prime numbers that occupy prime
+	// numbered position in sequence of prime numbers.
+	for (int k = 0; k < j; k++)
+		if (isPrime[k + 1])
+			cout << primes[k] << " ";
+}
+
+// Driven program
+int main()
+{
+	int n = 241;
+	cout << "Super-Primes less than or equal to " << n
+		<< " are :" << endl;
+	superPrimes(n);
+	return 0;
+}
+
+