Algorithm

1. Start

2. Read input integer 'n'

3. If n is negative:
   a. Print an error message: "Error! Factorial of a negative number doesn't exist."
   b. Exit

4. Initialize a variable 'factorial' to 1

5. For i from 1 to n:
   a. Multiply 'factorial' by i
   b. (Repeat for each value of i)

6. Print the calculated factorial value

7. End

Code Examples

#1 Code Example-C++ programing Find the Factorial of a Given Number

Code - C++ Programming

#include <iostream>
using namespace std;

int main() {
    int n;
    long factorial = 1.0;

    cout << "Enter a positive integer: ";
    cin >> n;

    if (n < 0)
        cout << "Error! Factorial of a negative number doesn't exist.";
    else {
        for(int i = 1; i <= n; ++i) {
            factorial *= i;
        }
        cout << "Factorial of " << n << " = " << factorial;    
    }

    return 0;
}
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Output

x
–
+
cmd
Enter a positive integer: 4
Factorial of 4 = 24
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Demonstration

C++ programing Find the Factorial of a Given Number- DevsEnv