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.
class Solution {
public:
bool backspaceCompare(string s, string t) {
return build(s) == build(t);
}
string build(string s) {
string res;
for (char c : s) {
if (c != '#') {
res += c;
}
else if (!res.empty()) {
res.pop_back();
}
}
return res;
}
}
;Follow-up:
How would you optimize the solution if the input strings are very large?
