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An integer is said to be prime if it is divisible by only 1 and itself. For example,
2, 3, 5 and 7 are prime, but 4, 6, 8 and 9 are not.
a) Write a function that determines whether a number is prime.
b) Use this function in a program that determines and prints all the prime numbers between 2 and 10,000.


#include <iostream>
using std::cout;
using std::endl;

int total=0;

void isPrime (int num) {
  bool prime = true;
  for(int i=2 ; i<=num/2 ; i++) {
    if(num % i == 0) {
      prime = false;
    }
  }
  if(prime) {
    total++;
    cout << num << "\t";
  }
}

int main(void) {
  cout << "The prime numbers from 2 to 10000 are: ";
  cout << endl;

  for(int i=2 ; i<=10000 ; i++) {
    isPrime(i);
  }
  cout << endl;
  cout << "Total of " << total << " prime numbers between 2 and 10000.";

  return 0;
}