874. Backspace String Compare

难度: Easy

题目描述

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?

解题思路

代码实现

解决方案

java

class Solution {
    public boolean backspaceCompare(String s, String t) {

        LinkedList<Character> sStk = new LinkedList<>();
        LinkedList<Character> tStk = new LinkedList<>();
        char[] sCharArray = s.toCharArray();
        char[] tCharArray = t.toCharArray();
        for (char c : sCharArray) {
            switch (c) {
                case '#':
                    if(!sStk.isEmpty())
                    sStk.pop();
                    break;
                default:
                    sStk.push(c);
            }
        }
        for (char c : tCharArray) {
            switch (c) {
                case '#':
                if(!tStk.isEmpty())
                    tStk.pop();
                    break;
                default:
                    tStk.push(c);
            }
        }
        return Arrays.equals(sStk.toArray(), tStk.toArray());
    }
}