title: Program Page Replacement Algorithms Set 2 Fifo
signature: function programPageReplacementAlgorithmsSet2Fifo(pages, n, capacity) {
test_code: 
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  function convertToString(value) {
      return JSON.stringify(value, function (key, val) {
          if (val instanceof Set) {
              return Array.from(val);
          } return val;});
  }
  
  function validateSolution(actual, expected){
      return convertToString(actual)===convertToString(expected);
  }
  
  function driver(pages, n, capacity, expected){
      try{
          if (validateSolution(PLACEHOLDER_FN_NAME(pages, n, capacity),expected)){
              return "PASSED";
          }
          return "FAILED";
      } catch (error) {
        return error.name;
      }
      
  }
      
  function main(){
    let result = '';
    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);
    console.log(`TEST-0...${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);
    console.log(`TEST-1...${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);
    console.log(`TEST-2...${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);
    console.log(`TEST-3...${result}`);
  
    result = driver([-82, -70, -68, -56, -50, -44, 4, 18, 28, 30, 30, 42, 66, 78, 80], 9, 11, 9);
    console.log(`TEST-4...${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);
    console.log(`TEST-5...${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);
    console.log(`TEST-6...${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);
    console.log(`TEST-7...${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);
    console.log(`TEST-8...${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);
    console.log(`TEST-9...${result}`);
  
    process.exit(0);
  };
  
  if (require.main === module) {
    main();
  }
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;
  }