title: Program Page Replacement Algorithms Set 2 Fifo
signature: function program_page_replacement_algorithms_set_2_fifo(pages, n, capacity)
source_py: def program_page_replacement_algorithms_set_2_fifo(pages, n, capacity):
      s = set()
      indexes = Queue()
      page_faults = 0
      for i in range(n):
          if (len(s) < capacity):
              if (pages[i] not in s):
                  s.add(pages[i])
                  page_faults += 1
                  indexes.put(pages[i])
          elif (pages[i] not in s):
              val = indexes.queue[0]
              indexes.get()
              s.remove(val)
              s.add(pages[i])
              indexes.put(pages[i])
              page_faults += 1
      return page_faults
source_cpp: int program_page_replacement_algorithms_set_2_fifo(vector<int> pages, int n, int capacity) {
    unordered_set < int > s;
    queue < int > indexes;
    int page_faults = 0;
    for ( int i = 0;
    i < n;
    i ++ ) {
      if ( s . size ( ) < capacity ) {
        if ( s . find ( pages [ i ] ) == s . end ( ) ) {
          s . insert ( pages [ i ] );
          page_faults ++;
          indexes . push ( pages [ i ] );
        }
      }
      else {
        if ( s . find ( pages [ i ] ) == s . end ( ) ) {
          int val = indexes . front ( );
          indexes . pop ( );
          s . erase ( val );
          s . insert ( pages [ i ] );
          indexes . push ( pages [ i ] );
          page_faults ++;
        }
      }
    }
    return page_faults;
  }
question_info.entry_fn_name: program_page_replacement_algorithms_set_2_fifo
question_info.entry_cls_name: Solution
question_info.test_case_ids: ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
question_info.test_code: 
  
  -- SOLUTION CODE
  -- ============================================
  PLACEHOLDER_CODE_BODY
  
  -- TESTING CODE 
  -- ============================================
  function isCorrect(actual, expected)
      if type(expected) ~= type(actual) then
          return false
      end
      
      if type(expected) == 'table' then
          for k,v_expected in pairs(expected) do
              
              if actual[k] == nil then
                  return false
              end
              local v_actual = actual[k]
              if not isCorrect(v_actual, v_expected) then
                  return false
              end
              actual[k]=nil
          end
      
          if next(actual) then 
              return false
          end
          return true
      else
          return actual == expected
      end
  end
  
  function validateSolution(actual, expected)
      return isCorrect(actual,expected)
  end
  
  function driver(pages, n, capacity, expected)
      local exec_result;
      local status, error_msg = pcall(function () 
          exec_result=PLACEHOLDER_FN_NAME(pages, n, capacity) 
      end)
      if status then
          if validateSolution(exec_result,expected) then
              return "PASSED"
          end
          return "FAILED"
      else
          return string.format("ERROR=%s",string.gsub(error_msg,".*:[%d]+: ",""))
      end
  end
      
  function main()
      result = driver({4, 4, 6, 7, 8, 11, 13, 18, 26, 35, 36, 37, 45, 46, 46, 47, 48, 49, 51, 52, 53, 56, 61, 74, 75, 77, 80, 83, 85, 86, 87, 90, 93, 95, 97, 98, 99, 99}, 36, 37, 34)
      print(string.format("TEST-0...%s",result))
  
      result = driver({78, -48, 50, -20, -6, 58, -8, 66, 72, 68, 4, 80, 58, -26, -82, -56, 92, 76, 20, 82, -46, 86, 38, 60, -62, -48, 76, 8, -66, -4, -98, -96, -52, 92}, 33, 23, 30)
      print(string.format("TEST-1...%s",result))
  
      result = driver({0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1}, 19, 13, 2)
      print(string.format("TEST-2...%s",result))
  
      result = driver({98, 78, 94, 42, 62, 83, 7, 62, 60, 94, 16, 28, 50, 15, 18, 71, 86, 47, 62, 89}, 15, 11, 13)
      print(string.format("TEST-3...%s",result))
  
      result = driver({-82, -70, -68, -56, -50, -44, 4, 18, 28, 30, 30, 42, 66, 78, 80}, 9, 11, 9)
      print(string.format("TEST-4...%s",result))
  
      result = driver({1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0}, 25, 25, 2)
      print(string.format("TEST-5...%s",result))
  
      result = driver({4, 5, 13, 15, 18, 28, 32, 40, 46, 46, 55, 57, 61, 63, 65, 68, 77, 79, 79, 96}, 17, 18, 16)
      print(string.format("TEST-6...%s",result))
  
      result = driver({-2, 82, 2, -74, -6, -24, 54, -74, -98, 8, -94, -60, -42, -38, 36, -38, -58, -70, -28, -34, 70, -6, -2, -76, -40, -4, 0, -4, 76, 48, -34, -26, -48, -58, -88, -44, 20, -22, 78}, 31, 24, 25)
      print(string.format("TEST-7...%s",result))
  
      result = driver({0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, 26, 24, 2)
      print(string.format("TEST-8...%s",result))
  
      result = driver({4, 90, 28, 71, 69, 45, 92, 63, 72, 76, 47, 85, 36, 59, 88, 46, 28, 19, 50, 31, 63, 13}, 15, 12, 15)
      print(string.format("TEST-9...%s",result))
  
  end
  
  main()
question_info.test_list: [{"idx": 0, "outputs": 34, "inputs": {"pages": [4, 4, 6, 7, 8, 11, 13, 18, 26, 35, 36, 37, 45, 46, 46, 47, 48, 49, 51, 52, 53, 56, 61, 74, 75, 77, 80, 83, 85, 86, 87, 90, 93, 95, 97, 98, 99, 99], "n": 36, "capacity": 37}}, {"idx": 1, "outputs": 30, "inputs": {"pages": [78, -48, 50, -20, -6, 58, -8, 66, 72, 68, 4, 80, 58, -26, -82, -56, 92, 76, 20, 82, -46, 86, 38, 60, -62, -48, 76, 8, -66, -4, -98, -96, -52, 92], "n": 33, "capacity": 23}}, {"idx": 2, "outputs": 2, "inputs": {"pages": [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1], "n": 19, "capacity": 13}}, {"idx": 3, "outputs": 13, "inputs": {"pages": [98, 78, 94, 42, 62, 83, 7, 62, 60, 94, 16, 28, 50, 15, 18, 71, 86, 47, 62, 89], "n": 15, "capacity": 11}}, {"idx": 4, "outputs": 9, "inputs": {"pages": [-82, -70, -68, -56, -50, -44, 4, 18, 28, 30, 30, 42, 66, 78, 80], "n": 9, "capacity": 11}}, {"idx": 5, "outputs": 2, "inputs": {"pages": [1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0], "n": 25, "capacity": 25}}, {"idx": 6, "outputs": 16, "inputs": {"pages": [4, 5, 13, 15, 18, 28, 32, 40, 46, 46, 55, 57, 61, 63, 65, 68, 77, 79, 79, 96], "n": 17, "capacity": 18}}, {"idx": 7, "outputs": 25, "inputs": {"pages": [-2, 82, 2, -74, -6, -24, 54, -74, -98, 8, -94, -60, -42, -38, 36, -38, -58, -70, -28, -34, 70, -6, -2, -76, -40, -4, 0, -4, 76, 48, -34, -26, -48, -58, -88, -44, 20, -22, 78], "n": 31, "capacity": 24}}, {"idx": 8, "outputs": 2, "inputs": {"pages": [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1], "n": 26, "capacity": 24}}, {"idx": 9, "outputs": 15, "inputs": {"pages": [4, 90, 28, 71, 69, 45, 92, 63, 72, 76, 47, 85, 36, 59, 88, 46, 28, 19, 50, 31, 63, 13], "n": 15, "capacity": 12}}]