Backspace String Compare
Given two strings containing backspace characters, compare the final strings after applying the backspace operations.
Constraints:
- 1 <= s.length, t.length <= 200
- s and t only contain lowercase letters and '#' characters.
Examples:
Input: "ab#c","ad#c"
Output: true
Explanation: Applying the backspace operations, we get "ac" for both strings.
Solutions
Two-Pointer Approach
Time: O(n + m)Space: O(n + m)
We use a two-pointer approach to build the final strings after applying the backspace operations. We iterate through each string, and whenever we encounter a '#', we remove the last character from the string if it's not empty.
def backspaceCompare(s, t):
def build(s):
stack = []
for char in s:
if char != '#':
stack.append(char)
elif stack:
stack.pop()
return ''.join(stack)
return build(s) == build(t)Follow-up:
How would you optimize the solution if the input strings are very large?
