Revert "style: remove interaction with the user (TheAlgorithms#3006)"

This reverts commit bde09c2.

Author: realstealthninja

math/number_of_positive_divisors.cpp

@@ -23,6 +23,7 @@
 **/
 
 #include <cassert>
+#include <iostream>
 
 /**
  * Function to compute the number of positive divisors.
@@ -79,5 +80,13 @@ void tests() {
  */
 int main() {
     tests();
+    int n;
+    std::cin >> n;
+    if (n == 0) {
+        std::cout << "All non-zero numbers are divisors of 0 !" << std::endl;
+    } else {
+        std::cout << "Number of positive divisors is : ";
+        std::cout << number_of_positive_divisors(n) << std::endl;
+    }
     return 0;
 }