how to get prime number in c++ code example
Example 1: c++ find prime numbers
#include <iostream>
using namespace std;
int main()
{
int n, i;
bool isPrime = true;
cout << "Enter a positive integer: ";
cin >> n;
for(i = 2; i <= n / 2; ++i)
{
if(n % i == 0)
{
isPrime = false;
break;
}
}
if (isPrime)
cout << "This is a prime number";
else
cout << "This is not a prime number";
return 0;
}
Example 2: check prime number c++
#include <iostream>
using namespace std;
int main() {
int i, n;
bool isPrime = true;
cout << "Enter a positive integer: ";
cin >> n;
if (n == 0 || n == 1) {
isPrime = false;
}
else {
for (i = 2; i <= n / 2; ++i) {
if (n % i == 0) {
isPrime = false;
break;
}
}
}
if (isPrime)
cout << n << " is a prime number";
else
cout << n << " is not a prime number";
return 0;
}
Example 3: c++ program to generate prime numbers
#include <iostream>
using namespace std;
int main() {
int low, high, i;
bool isPrime = true;
cout << "Enter two numbers (intervals): ";
cin >> low >> high;
cout << "\nPrime numbers between " << low << " and " << high << " are: " << endl;
while (low < high) {
isPrime = true;
if (low == 0 || low == 1) {
isPrime = false;
}
else {
for (i = 2; i <= low / 2; ++i) {
if (low % i == 0) {
isPrime = false;
break;
}
}
}
if (isPrime)
cout << low << " ";
++low;
}
return 0;
}