title: Find The First Missing Number
signature: function findTheFirstMissingNumber(array, start, end_arg2) {
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 );
  }