title: C Program Factorial Number
signature: pub fn c_program_factorial_number(n: i32) -> i32 {
test_code: use std::collections::HashMap;
  use std::collections::HashSet;
  use std::cmp::*;
  use std::collections::*;
  use std::fmt::*; 
  
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  pub fn validate_solution(actual: i32, expected: i32)->bool{
  return actual==expected
  }
  pub fn driver(n: i32, expected: i32)->String{
      if validate_solution(PLACEHOLDER_FN_NAME(n), expected) {
        return "PASSED".to_string();
      };
      return "FAILED".to_string();
  
  }
  
  fn main() {
      println!("TEST-0...{}", driver(
        5, 
        120
      ));
      
      println!("TEST-1...{}", driver(
        12, 
        479001600
      ));
      
  }
source_py: def c_program_factorial_number(n):
      return (1 if ((n == 1) or (n == 0)) else (n * c_program_factorial_number((n - 1))))
source_cpp: unsigned int c_program_factorial_number(unsigned int n) {
    if ( n == 0 ) return 1;
    return n * c_program_factorial_number ( n - 1 );
  }