title: Nth Pentagonal Number
signature: float nthPentagonalNumber(int n) {
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(float actual, float expected){
      return abs(actual - expected) < 1e-06;
  }
  
  string driver(int n, float expected){
      try
      {
          if (validateSolution(PLACEHOLDER_FN_NAME(n), 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(96, 13776.0); 
      cout << "TEST-" << 0 << "..."
           <<  result
           << "\n";
  
      result = driver(93, 12927.0); 
      cout << "TEST-" << 1 << "..."
           <<  result
           << "\n";
  
      result = driver(15, 330.0); 
      cout << "TEST-" << 2 << "..."
           <<  result
           << "\n";
  
      result = driver(8, 92.0); 
      cout << "TEST-" << 3 << "..."
           <<  result
           << "\n";
  
      result = driver(21, 651.0); 
      cout << "TEST-" << 4 << "..."
           <<  result
           << "\n";
  
      result = driver(14, 287.0); 
      cout << "TEST-" << 5 << "..."
           <<  result
           << "\n";
  
      result = driver(11, 176.0); 
      cout << "TEST-" << 6 << "..."
           <<  result
           << "\n";
  
      result = driver(79, 9322.0); 
      cout << "TEST-" << 7 << "..."
           <<  result
           << "\n";
  
      result = driver(24, 852.0); 
      cout << "TEST-" << 8 << "..."
           <<  result
           << "\n";
  
      result = driver(94, 13207.0); 
      cout << "TEST-" << 9 << "..."
           <<  result
           << "\n";
  
      return 0;
  }
source_py: def nth_pentagonal_number(n):
      return ((((3 * n) * n) - n) / 2)
source_cpp: int nth_pentagonal_number(int n) {
    return ( 3 * n * n - n ) / 2;
  }