title: C Program Factorial Number 1
signature: pub fn c_program_factorial_number_1(n: i32) -> i64 {
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: i64, expected: i64)->bool{
  return actual==expected
  }
  pub fn driver(n: i32, expected: i64)->String{
      if validate_solution(PLACEHOLDER_FN_NAME(n), expected) {
        return "PASSED".to_string();
      };
      return "FAILED".to_string();
  
  }
  
  fn main() {
      println!("TEST-0...{}", driver(
        15, 
        1307674368000
      ));
      
      println!("TEST-1...{}", driver(
        7, 
        5040
      ));
      
      println!("TEST-2...{}", driver(
        16, 
        20922789888000
      ));
      
      println!("TEST-3...{}", driver(
        16, 
        20922789888000
      ));
      
  }
source_py: def c_program_factorial_number_1(n):
      return (1 if ((n == 1) or (n == 0)) else (n * c_program_factorial_number_1((n - 1))))
source_cpp: unsigned int c_program_factorial_number_1(unsigned int n) {
    int res = 1, i;
    for ( i = 2;
    i <= n;
    i ++ ) res *= i;
    return res;
  }