844. Backspace String Compare LeetCode Problem (Java)

Problem Statement: 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.

hint: Stack or StringBuilder or Two Pointers or arrays.

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Constraints:

• 1 <= s.length, t.length <= 200
• s and t only contain lowercase letters and '#' characters.

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".

Solution:

class Solution {
    public boolean backspaceCompare(String s, String t) {
        Stack<Character> stk1=new Stack<>();
        Stack<Character> stk2=new Stack<>();
        for(char c:s.toCharArray()){
            if(c!='#')
                stk1.push(c);
            else
                if(!stk1.isEmpty()) stk1.pop();
        }
        for(char c:t.toCharArray()){
            if(c!='#')
                stk2.push(c);
            else
                if(!stk2.isEmpty()) stk2.pop();
        }
        if(stk1.equals(stk2)) return true;
        return false;
    }
}