Backspace String Compare
Difficulty: Easy
Category: DSA
Topics: Two Pointers, String, Stack, Simulation
Asked at: Facebook, Google, Amazon, Oracle
Given two strings `s` and `t`, return `true` _if they are equal when both are typed into empty text editors_. `'#'` means a backspace character.
Note that after backspacing an empty text, the text will continue empty.
**Example 1:**
**Input:** s = "ab#c", t = "ad#c"
**Output:** true
**Explanation:** Both s and t become "ac".
```
**Example 2:**
**Input:** s = "ab##", t = "c#d#"
**Output:** true
**Explanation:** Both s and t become "".
```
**Example 3:**
**Input:** s = "a#c", t = "b"
**Output:** false
**Explanation:** s becomes "c" while t becomes "b".
```
**Constraints:**
- `1 <= s.length, t.length <= 200`
- `s` and `t` only contain lowercase letters and `'#'` characters.
**Follow up:** Can you solve it in `O(n)` time and `O(1)` space?