title: Count Ofdifferent Ways Express N Sum 1 3 4
signature: class Solution {
  
      public long CountOfdifferentWaysExpressNSum134(int n) {
test_code: using System;
  using System.Numerics;
  using System.Diagnostics;
  using System.Collections.Generic;
  using System.Linq;
  using System.Text;
  using System.Security.Cryptography;
  using System.Web.UI;
  using System.Web.Script.Serialization;
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  namespace EvaluatePrediction {
      class TestRunner {
          public bool ValidateSolution(long actual, long expected){
              return new JavaScriptSerializer().Serialize(actual) == new JavaScriptSerializer().Serialize(expected);
          }
  
          public string driver(int n, long expected){
              try{
                PLACEHOLDER_CLS_NAME solution_cls = new PLACEHOLDER_CLS_NAME();
                long pred_result = solution_cls.PLACEHOLDER_FN_NAME(n); 
                if (ValidateSolution(
                      pred_result,
                      expected)){
                  return "PASSED";
                }
                return "FAILED";
              } 
              catch (Exception exception_obj)
              {
                return exception_obj.GetType().FullName;
              }
          }
          static void Main(string[] args) {
              TestRunner runner = new TestRunner();
              String result;
              result = runner.driver(
                  44, 
                  821223649
              );
              Console.WriteLine(string.Format(
                  "TEST-0...{0}",
                  result)
              );result = runner.driver(
                  9, 
                  40
              );
              Console.WriteLine(string.Format(
                  "TEST-1...{0}",
                  result)
              );result = runner.driver(
                  19, 
                  4895
              );
              Console.WriteLine(string.Format(
                  "TEST-2...{0}",
                  result)
              );result = runner.driver(
                  10, 
                  64
              );
              Console.WriteLine(string.Format(
                  "TEST-3...{0}",
                  result)
              );result = runner.driver(
                  78, 
                  10472279279564025
              );
              Console.WriteLine(string.Format(
                  "TEST-4...{0}",
                  result)
              );result = runner.driver(
                  70, 
                  222915410843904
              );
              Console.WriteLine(string.Format(
                  "TEST-5...{0}",
                  result)
              );result = runner.driver(
                  81, 
                  44361286907595736
              );
              Console.WriteLine(string.Format(
                  "TEST-6...{0}",
                  result)
              );result = runner.driver(
                  81, 
                  44361286907595736
              );
              Console.WriteLine(string.Format(
                  "TEST-7...{0}",
                  result)
              );result = runner.driver(
                  49, 
                  9107509825
              );
              Console.WriteLine(string.Format(
                  "TEST-8...{0}",
                  result)
              );
          }
      }
  }
  
source_py: def count_ofdifferent_ways_express_n_sum_1_3_4(n):
      DP = [0 for i in range(0, (n + 1))]
      DP[0] = DP[1] = DP[2] = 1
      DP[3] = 2
      for i in range(4, (n + 1)):
          DP[i] = ((DP[(i - 1)] + DP[(i - 3)]) + DP[(i - 4)])
      return DP[n]
source_cpp: int count_ofdifferent_ways_express_n_sum_1_3_4(int n) {
    int DP [ n + 1 ];
    DP [ 0 ] = DP [ 1 ] = DP [ 2 ] = 1;
    DP [ 3 ] = 2;
    for ( int i = 4;
    i <= n;
    i ++ ) DP [ i ] = DP [ i - 1 ] + DP [ i - 3 ] + DP [ i - 4 ];
    return DP [ n ];
  }