Leetcode #2546: Apply Bitwise Operations to Make Strings Equal
In this guide, we solve Leetcode #2546 Apply Bitwise Operations to Make Strings Equal in Python and focus on the core idea that makes the solution efficient.
You will see the intuition, the step-by-step method, and a clean Python implementation you can use in interviews.
Problem Statement
You are given two 0-indexed binary strings s and target of the same length n. You can do the following operation on s any number of times: Choose two different indices i and j where 0 <= i, j < n.
Quick Facts
- Difficulty: Medium
- Premium: No
- Tags: Bit Manipulation, String
Intuition
The problem structure lets us track state with bitwise operations.
Bit operations are constant time and avoid extra memory.
Approach
Apply XOR/AND/OR and shifts to maintain the required invariant.
Aggregate the result in a single pass.
Steps:
- Identify a bitwise invariant.
- Combine values with bit operations.
- Return the aggregated result.
Example
Input: s = "1010", target = "0110"
Output: true
Explanation: We can do the following operations:
- Choose i = 2 and j = 0. We have now s = "0010".
- Choose i = 2 and j = 1. We have now s = "0110".
Since we can make s equal to target, we return true.
Python Solution
class Solution:
def makeStringsEqual(self, s: str, target: str) -> bool:
return ("1" in s) == ("1" in target)
Complexity
The time complexity is , where is the length of the string. The space complexity is .
Edge Cases and Pitfalls
Watch for boundary values, empty inputs, and duplicate values where applicable. If the problem involves ordering or constraints, confirm the invariant is preserved at every step.
Summary
This Python solution focuses on the essential structure of the problem and keeps the implementation interview-friendly while meeting the constraints.