Count Numbers With Distinct Neighbors

Count integers from left through right, including both endpoints, that have no equal neighboring digits. Use their usual decimal writing with no leading zeroes. Zero and all other single-digit numbers qualify.

Implement counting_numbers(left, right).

Input

left: The first allowed value.

right: The last allowed value.

Output

Return how many values satisfy the rule.

Ограничения

0 ≤ left ≤ right ≤ 10¹⁸. The range may be too large to inspect each integer individually.

Примеры

Ввод:
left = 10
right = 15

Ожидаемый вывод:
expected = 5

Ввод:
long long left = 10;
long long right = 15;

Ожидаемый вывод:
long long expected = 5;

Ввод:
long left = 10;
long right = 15;

Ожидаемый вывод:
long expected = 5;

Ввод:
left = 0
right = 9

Ожидаемый вывод:
expected = 10

Ввод:
long long left = 0;
long long right = 9;

Ожидаемый вывод:
long long expected = 10;

Ввод:
long left = 0;
long right = 9;

Ожидаемый вывод:
long expected = 10;

Ссылки

Это задание адаптировано для CodeUtility. Следуйте условию и ограничениям выше.

• Counting Numbers — 2220