Problem

Given a positive integer num represented as a string, return the integer num without trailing zeros as a string.

Example 1:

Input: num = “51230100” Output: “512301” Explanation: Integer “51230100” has 2 trailing zeros, we remove them and return integer “512301”.

Example 2:

Input: num = “123” Output: “123” Explanation: Integer “123” has no trailing zeros, we return integer “123”.

Constraints:

1 <= num.length <= 1000 num consists of only digits. num doesn’t have any leading zeros.

Pre analysis

will count number of zeros from end and will return substring from 0 to len - count