/* Write a C++ program to calculate the factorial of a number */
 
#include <iostream>
using namespace std;
 
int main() {
    int n;
    long long factorial = 1;
 
    cout << "Enter a positive integer: ";
    cin >> n;
 
    if (n < 0) {
        cout << "Factorial is not defined for negative numbers." << endl;
    } else {
        for (int i = 1; i <= n; i++) {
            factorial *= i;
        }
        cout << "Factorial of " << n << " = " << factorial << endl;
    }
 
    return 0;
}
 

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