title: Count Factorial Numbers In A Given Range
signature: pub fn count_factorial_numbers_in_a_given_range(low: i32, high: 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(low: i32, high: i32, expected: i32)->String{
      if validate_solution(PLACEHOLDER_FN_NAME(low, high), expected) {
        return "PASSED".to_string();
      };
      return "FAILED".to_string();
  
  }
  
  fn main() {
      println!("TEST-0...{}", driver(
        57, 79, 
        0
      ));
      
      println!("TEST-1...{}", driver(
        57, 21, 
        0
      ));
      
      println!("TEST-2...{}", driver(
        31, 37, 
        0
      ));
      
      println!("TEST-3...{}", driver(
        62, 87, 
        0
      ));
      
      println!("TEST-4...{}", driver(
        49, 98, 
        0
      ));
      
      println!("TEST-5...{}", driver(
        82, 76, 
        0
      ));
      
      println!("TEST-6...{}", driver(
        31, 45, 
        0
      ));
      
      println!("TEST-7...{}", driver(
        5, 52, 
        2
      ));
      
      println!("TEST-8...{}", driver(
        76, 43, 
        0
      ));
      
      println!("TEST-9...{}", driver(
        55, 6, 
        0
      ));
      
  }
source_py: def count_factorial_numbers_in_a_given_range(low, high):
      fact = 1
      x = 1
      while (fact < low):
          fact = (fact * x)
          x += 1
      res = 0
      while (fact <= high):
          res += 1
          fact = (fact * x)
          x += 1
      return res
source_cpp: int count_factorial_numbers_in_a_given_range(int low, int high) {
    int fact = 1, x = 1;
    while ( fact < low ) {
      fact = fact * x;
      x ++;
    }
    int res = 0;
    while ( fact <= high ) {
      res ++;
      fact = fact * x;
      x ++;
    }
    return res;
  }