Условие
Data typed by people is messy. You get a list of strings and must add up the ones that are whole numbers, ignoring the rest instead of crashing.
An entry counts if, after removing spaces at both ends, it is an optional + or - sign followed by one or more digits. Anything else (empty text, decimals such as "2.5", words) is skipped.
Implement sum_valid_numbers(values).
Input
values: The entries to read.
Output
Return the sum of the valid whole numbers (0 if there are none).
Ограничения
0 ≤ number of entries ≤ 1,000
Each entry has at most 20 characters; valid numbers fit in a 64-bit integer
Примеры
Ввод:
values = ["10", " 5 ", "abc", "-3"]
Ожидаемый вывод:
expected = 12Ввод:
std::vector<std::string> values = {"10", " 5 ", "abc", "-3"};
Ожидаемый вывод:
long long expected = 12;Ввод:
string[] values = new string[] {"10", " 5 ", "abc", "-3"};
Ожидаемый вывод:
long expected = 12;Пояснение
"10", " 5 " (spaces are trimmed) and "-3" are whole numbers; "abc" is skipped. 10 + 5 - 3 = 12.
Ввод:
values = ["2.5", "", "seven"]
Ожидаемый вывод:
expected = 0Ввод:
std::vector<std::string> values = {"2.5", "", "seven"};
Ожидаемый вывод:
long long expected = 0;Ввод:
string[] values = new string[] {"2.5", "", "seven"};
Ожидаемый вывод:
long expected = 0;Пояснение
None of the entries is a whole number, so the sum is 0.
Как подступиться
Сначала попробуйте сами, затем открывайте подсказки по одной.
Подсказка 1
Strip the spaces first, then decide whether what is left is a valid whole number.
Подсказка 2
Converting inside try/except (or checking the characters) lets you skip bad entries without stopping.
Подсказка 3
Remember that a lone sign such as "+" is not a number.
Ожидаемая сложность
O(total length) time, O(1) extra space
Ссылки
Это задание адаптировано для CodeUtility. Следуйте условию и ограничениям выше.