title: Find Sum Modulo K First N Natural Number
signature: int findSumModuloKFirstNNaturalNumber(int n, int k) {
test_code: #include <algorithm>
  #include <assert.h>
  #include <cstdlib>
  #include <iostream>
  #include <map>
  #include <set>
  #include <string>
  #include <tuple> 
  #include <unordered_map>
  #include <vector>
  #include <math.h>
  #include <cmath>
  #include <bits/stdc++.h>
  #include <numeric>
  #include <functional>
  
  using namespace std;
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  bool validateSolution(int actual, int expected){
      return actual == expected;
  }
  
  string driver(int n, int k, int expected){
      try
      {
          if (validateSolution(PLACEHOLDER_FN_NAME(n, k), expected)){
              return "PASSED";
          }
          return "FAILED";
      }
      catch (const std::overflow_error& exception_obj)
      {
          return typeid(exception_obj).name();
      }
      catch (const std::runtime_error& exception_obj)
      {
          return typeid(exception_obj).name();
      }
      catch (const std::exception& exception_obj)
      {
          return typeid(exception_obj).name();
      }
      catch (...)
      {
          return "UNK_ERROR";
      }
  }
  
  int main() {
      string result = "";
  
      result = driver(11, 5, 21); 
      cout << "TEST-" << 0 << "..."
           <<  result
           << "\n";
  
      result = driver(36, 69, 666); 
      cout << "TEST-" << 1 << "..."
           <<  result
           << "\n";
  
      result = driver(71, 28, 876); 
      cout << "TEST-" << 2 << "..."
           <<  result
           << "\n";
  
      result = driver(74, 1, 0); 
      cout << "TEST-" << 3 << "..."
           <<  result
           << "\n";
  
      result = driver(66, 84, 2211); 
      cout << "TEST-" << 4 << "..."
           <<  result
           << "\n";
  
      result = driver(38, 14, 237); 
      cout << "TEST-" << 5 << "..."
           <<  result
           << "\n";
  
      result = driver(2, 11, 3); 
      cout << "TEST-" << 6 << "..."
           <<  result
           << "\n";
  
      result = driver(73, 87, 2701); 
      cout << "TEST-" << 7 << "..."
           <<  result
           << "\n";
  
      result = driver(79, 11, 388); 
      cout << "TEST-" << 8 << "..."
           <<  result
           << "\n";
  
      result = driver(30, 55, 465); 
      cout << "TEST-" << 9 << "..."
           <<  result
           << "\n";
  
      return 0;
  }
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;
  }