Language: "C programming"

please read it carefully and make sure the code is running by doing what's inside the sample output.

thanks,

1. Factorial (fact.c) The factorial of a positive integer is defined as n! nn -1n 2.1 and by definition 0! Write a program that prompts the user to enter an integer number and uses a function, factorial, described below, to calculate the factorial of that number. Implement this function: long factorial(int n) Sample Output: Number to calculate for: 5 5!120 Data Type Requirement: Input data for the factorial function is of type int, output is of type long. Input Validation: Input value must be greater than equal to 0