Factorial in C++

Published on 09 October 2019 (Updated: 10 October 2022)

Welcome to the Factorial in C++ page! Here, you'll find the source code for this program as well as a description of how the program works.

Current Solution

#include <iostream>
#include <cstdlib>
using namespace std;

int main(int argc, char *argv[])
{
    if (argc < 2 || std::string(argv[1]) == "")
    {
        cout << "Usage: please input a non-negative integer" << endl;
        return 1;
    }

    int n = atoi(argv[1]);
    if (n == 0 && std::string(argv[1]) != "0")
    {
        cout << "Usage: please input a non-negative integer" << endl;
        return 1;
    }
    if (n < 0)
    {
        cout << "Usage: please input a non-negative integer" << endl;
        return 1;
    }
    int i, fact = 1;
    for (i = 1; i <= n; i++)
    {
        fact = fact * i;
    }
    cout << fact << endl;
    return 0;
}

Factorial in C++ was written by:

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How to Implement the Solution

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How to Run the Solution

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