title: Find The First Missing Number
signature: function findTheFirstMissingNumber(array, start, end_arg2) {
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(array, start, end_arg2, expected){
      try{
          if (validateSolution(PLACEHOLDER_FN_NAME(array, start, end_arg2),expected)){
              return "PASSED";
          }
          return "FAILED";
      } catch (error) {
        return error.name;
      }
      
  }
      
  function main(){
    let result = '';
    result = driver([3, 6, 7, 9, 11, 14, 18, 30, 30, 32, 32, 34, 37, 44, 45, 45, 48, 48, 48, 52, 58, 60, 63, 67, 69, 69, 81, 83, 87, 89, 97, 99], 24, 18, 19);
    console.log(`TEST-0...${result}`);
  
    result = driver([88, -62, 16, 80, 66, 78, 88, 38, 52, -96, 48, 98, 96, -62, 18, 34, -58, 30, -10, 26, -98, 48, -96, 4, 92, 36, 36, -36, -32, -70, 62, -58, -58, -84, 86, -98], 19, 26, 19);
    console.log(`TEST-1...${result}`);
  
    result = driver([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, 1, 1, 1, 1, 1, 1, 1], 26, 28, 26);
    console.log(`TEST-2...${result}`);
  
    result = driver([79, 99, 79, 85, 61, 58, 62, 61, 39, 87, 39, 74, 36, 70, 30, 43, 20, 52, 54, 50, 81, 98, 42], 20, 20, 20);
    console.log(`TEST-3...${result}`);
  
    result = driver([-98, -72, -46, -44, -42, -40, -16, -4, 62, 70, 74], 8, 10, 8);
    console.log(`TEST-4...${result}`);
  
    result = driver([1, 1, 0, 1, 0, 0, 0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0], 26, 23, 24);
    console.log(`TEST-5...${result}`);
  
    result = driver([58], 0, 0, 0);
    console.log(`TEST-6...${result}`);
  
    result = driver([4, -84, -42, 12, -50, 42, -36, -38, -36, 98, -2, 20, 6, -96, -78, 24, 34, 88, 0, 74, 0, -8, -86, -68, -42, 98, -26, 86, -70, -32, -82, 78, 46, 58, 84, 4, -60, -90, -52, -78], 37, 31, 32);
    console.log(`TEST-7...${result}`);
  
    result = driver([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, 1], 28, 28, 28);
    console.log(`TEST-8...${result}`);
  
    result = driver([8], 0, 0, 0);
    console.log(`TEST-9...${result}`);
  
    process.exit(0);
  };
  
  if (require.main === module) {
    main();
  }
source_py: def find_the_first_missing_number(array, start, end):
      if (start > end):
          return (end + 1)
      if (start != array[start]):
          return start
      mid = int(((start + end) / 2))
      if (array[mid] == mid):
          return find_the_first_missing_number(array, (mid + 1), end)
      return find_the_first_missing_number(array, start, mid)
source_cpp: int find_the_first_missing_number(vector<int> array, int start, int end) {
    if ( start > end ) return end + 1;
    if ( start != array [ start ] ) return start;
    int mid = ( start + end ) / 2;
    if ( array [ mid ] == mid ) return find_the_first_missing_number ( array, mid + 1, end );
    return find_the_first_missing_number ( array, start, mid );
  }