[New] Prime Numbers

Author: SamuelMuloki

perfectNumbers/main.cpp

@@ -0,0 +1,35 @@
+//
+//  main.cpp
+//  perfectNumbers
+//
+//  Created by samuel muloki on 12/05/2019.
+//  Copyright © 2019 line23. All rights reserved.
+//
+
+/* Note : According to Wikipedia : In number theory, a perfect number is a positive integer
+that is equal to the sum of its proper positive divisors, that is, the sum of its positive
+divisors excluding the number itself (also known as its aliquot sum). Equivalently, a
+perfect number is a number that is half the sum of all of its positive divisors (including
+itself).
+ */
+
+#include <iostream>
+
+using namespace std;
+
+int main(int argc, const char * argv[]) {
+    int num, i=1, sum=0;
+    cout <<"Enter a number: ";
+    cin >> num;
+    while(i < num) {
+        if (num % i == 0)
+            sum = sum + i;
+            i++;
+    }
+    if (sum == num && sum != 0) {
+        cout <<num<<" is a perfect number";
+    } else
+        cout <<num<<" is not a perfect number";;
+    cout <<endl<<endl;
+    return 0;
+}

primeNumbers/main.cpp

@@ -0,0 +1,31 @@
+//
+//  main.cpp
+//  primeNumbers
+//
+//  Created by samuel muloki on 12/05/2019.
+//  Copyright © 2019 line23. All rights reserved.
+//
+
+#include <iostream>
+
+using namespace std;
+
+int main(int argc, const char * argv[]) {
+    int i, num;
+    cout <<"Enter any number: ";
+    cin >> num;
+    if (num == 1) {
+        cout <<"Smallest prime number is 2";
+    }
+    for (i = 2; i < num; i++) {
+        if (num % i == 0) {
+            cout <<num<<" is not a prime number";
+            break;
+        }
+    }
+    if (num == i) {
+        cout <<num<<" is a prime number";
+    }
+    cout <<endl<<endl;
+    return 0;
+}