Given a number, the task is to find the Factorial of this number using Command Line Arguments. Factorial of a non-negative integer is the multiplication of all integers smaller than or equal to n.
Examples:
Input: 3
Output: 6
1 * 2 * 3 = 6Input: 6
Output: 720
1 * 2 * 3 * 4 * 5 * 6 = 720
Approach:
- Since the number is entered as Command line Argument, there is no need for a dedicated input line
- Extract the input number from the command line argument
- This extracted number will be in String type.
- Convert this number into integer type and store it in a variable, say num
- Find the reverse of this number and store in a variable, say rev_num
- Check if this rev_num and num are same or not.
- If they are not same, the number is not Palindrome
- If they are same, the number is a Palindrome
Program:
C
// C program to find factorial of a number // using command line arguments #include <stdio.h> #include <stdlib.h> /* atoi */ // Function to find factorial of given number unsigned int factorial(unsigned int n)
{ int res = 1, i;
for (i = 2; i <= n; i++)
res *= i;
return res;
} // Driver code int main( int argc, char * argv[])
{ int num, res = 0;
// Check if the length of args array is 1
if (argc == 1)
printf ( "No command line arguments found.\n" );
else {
// Get the command line argument and
// Convert it from string type to integer type
// using function "atoi( argument)"
num = atoi (argv[1]);
// Find the factorial
printf ( "%d\n" , factorial(num));
}
return 0;
} |
Java
// Java program to find the factorial of a number // using command line arguments class GFG {
// Method to find factorial of given number
static int factorial( int n)
{
int res = 1 , i;
for (i = 2 ; i <= n; i++)
res *= i;
return res;
}
// Driver code
public static void main(String[] args)
{
// Check if length of args array is
// greater than 0
if (args.length > 0 ) {
// Get the command line argument and
// Convert it from string type to integer type
int num = Integer.parseInt(args[ 0 ]);
// Get the command line argument
// and find the factorial
System.out.println(factorial(num));
}
else
System.out.println( "No command line "
+ "arguments found." );
}
} |
Python
# Python program to find factorial of a number # using command line arguments import sys
# Function to find factorial of given number def factorial(n):
res = 1
for i in range ( 2 , n + 1 ):
res * = i
return res
# Driver code if __name__ = = "__main__" :
# Check if command line argument is provided
if len (sys.argv) = = 1 :
print ( "No command line arguments found." )
else :
# Get the command line argument and
# Convert it from string type to integer type
num = int (sys.argv[ 1 ])
# Find the factorial
print (factorial(num))
|
Output:
-
In C:
-
In Java:
- In Python
Time Complexity: O(N)
Auxiliary Space: O(1)