- 0007_reverse_integer
- 0009_palindrome_number
- 0013_roman_to_integer
- 0067_add_binary
- 0069_sqrtx
- 0149_max_points_on_a_line
- 0168_excel_sheet_column_title
- 0172_factorial_trailling_zeros
- 0202_happy_numbers
- 0204_count_primes
- 0231_power_of_two
- 0258_add_digits
- 0263_ugly_number
- 0268_missing_number
- 0326_power_of_three
- 0367_valid_perfect_square
- 0441_arranging_coins
- 0453_minimum_moves_to_equal_array_elements
- 0507_perfect_number