Is Add Binary easy or hard?

Add Binary is classified as an easy problem. The logic is straightforward once you understand binary addition and carry propagation, making it a common warm-up problem for string and bit manipulation practice.

Add Binary Python/Java solution

In Python, iterate from the end of both strings while tracking a carry and append result bits to a list. In Java, use a StringBuilder and perform the same digit-by-digit addition. Both implementations run in O(n) time and O(n) space.

How to solve Add Binary in O(n)?

Traverse both binary strings from the last character toward the first. Add the two bits along with a carry value, compute the result bit using sum % 2, and update carry with sum // 2. Continue until all digits and the carry are processed, producing an O(n) time solution.

What is the best approach for Add Binary?

The best approach is bit-by-bit addition with a carry, similar to manual binary addition. Traverse both strings from right to left, add digits with the carry, and append the resulting bit. This runs in O(n) time and O(n) space and demonstrates clear understanding of binary arithmetic.

Is Add Binary asked at Google/Amazon/Meta?

Add Binary is a common easy-level interview problem and has appeared in coding screens for companies like Amazon and Google. It tests understanding of binary arithmetic, string traversal, and carry handling rather than complex data structures.

What data structure is used in Add Binary?

The problem primarily uses strings for representing binary numbers. During computation, developers often use a string builder, array, or list to store result bits efficiently before reversing or joining them into the final string.

What is the time complexity of Add Binary?

The optimal solution runs in O(n) time where n is the length of the longer binary string. Each digit is processed exactly once while maintaining a carry. Space complexity is O(n) because the resulting binary string can be at most n+1 characters.

Description Solution Video 8:01

67. Add Binary

Easy58.4% acceptance17 companies

Given two binary strings a and b, return their sum as a binary string.

Example 1:

Input: a = "11", b = "1"
Output: "100"

Example 2:

Input: a = "1010", b = "1011"
Output: "10101"

Constraints:

1 <= a.length, b.length <= 10⁴
a and b consist only of '0' or '1' characters.
Each string does not contain leading zeros except for the zero itself.

Asked at 17 companies

Deloitte Walmart Labs Wipro

Google Amazon Microsoft Meta Bloomberg

TCS Adobe Visa Snapchat

+5 more

Capgemini Apple

Infosys

IBM Yandex

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8:01

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67. Add Binary

Asked at 17 companies

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