title: Find Sum Modulo K First N Natural Number
signature: pub fn find_sum_modulo_k_first_n_natural_number(n: i32, k: 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, k: i32, expected: i32)->String{
      if validate_solution(PLACEHOLDER_FN_NAME(n, k), expected) {
        return "PASSED".to_string();
      };
      return "FAILED".to_string();
  
  }
  
  fn main() {
      println!("TEST-0...{}", driver(
        11, 5, 
        21
      ));
      
      println!("TEST-1...{}", driver(
        36, 69, 
        666
      ));
      
      println!("TEST-2...{}", driver(
        71, 28, 
        876
      ));
      
      println!("TEST-3...{}", driver(
        74, 1, 
        0
      ));
      
      println!("TEST-4...{}", driver(
        66, 84, 
        2211
      ));
      
      println!("TEST-5...{}", driver(
        38, 14, 
        237
      ));
      
      println!("TEST-6...{}", driver(
        2, 11, 
        3
      ));
      
      println!("TEST-7...{}", driver(
        73, 87, 
        2701
      ));
      
      println!("TEST-8...{}", driver(
        79, 11, 
        388
      ));
      
      println!("TEST-9...{}", driver(
        30, 55, 
        465
      ));
      
  }
source_py: def find_sum_modulo_k_first_n_natural_number(N, K):
      ans = 0
      for i in range(1, (N + 1)):
          ans += (i % K)
      return ans
source_cpp: int find_sum_modulo_k_first_n_natural_number(int N, int K) {
    int ans = 0;
    for ( int i = 1;
    i <= N;
    i ++ ) ans += ( i % K );
    return ans;
  }