title: Find Sum Modulo K First N Natural Number 1
signature: function find_sum_modulo_k_first_n_natural_number_1(n, k)
test_code: using Printf
  
  # SOLUTION CODE
  # ============================================
  PLACEHOLDER_CODE_BODY
  
  # TESTING CODE 
  # ============================================
  function validate_solution(actual, expected)
      return actual == expected
  end
  
  function driver(n, k, expected)
      try
  
          if validate_solution(PLACEHOLDER_FN_NAME(n, k), expected)
              return "PASSED";
          end
          return "FAILED";
      catch exception_obj
          return string(Base.typename(typeof(exception_obj)).wrapper);
      end
  end
  
  function main()
      
      result = driver(40, 90, 2600);
      @printf("TEST-0...%s\n",result);
      
      result = driver(46, 64, 2530);
      @printf("TEST-1...%s\n",result);
      
      result = driver(97, 20, 1074);
      @printf("TEST-2...%s\n",result);
      
      result = driver(63, 1, 0);
      @printf("TEST-3...%s\n",result);
      
      result = driver(92, 52, 3166);
      @printf("TEST-4...%s\n",result);
      
      result = driver(60, 35, 1345);
      @printf("TEST-5...%s\n",result);
      
      result = driver(67, 40, 1684);
      @printf("TEST-6...%s\n",result);
      
      result = driver(61, 62, 3751);
      @printf("TEST-7...%s\n",result);
      
      result = driver(74, 61, 2311);
      @printf("TEST-8...%s\n",result);
      
      result = driver(67, 41, 1691);
      @printf("TEST-9...%s\n",result);
      
  end
  
  main()
source_py: def find_sum_modulo_k_first_n_natural_number_1(N, K):
      ans = 0
      y = (N / K)
      x = (N % K)
      ans = ((((K * (K - 1)) / 2) * y) + ((x * (x + 1)) / 2))
      return int(ans)
source_cpp: int find_sum_modulo_k_first_n_natural_number_1(int N, int K) {
    int ans = 0;
    int y = N / K;
    int x = N % K;
    ans = ( K * ( K - 1 ) / 2 ) * y + ( x * ( x + 1 ) ) / 2;
    return ans;
  }