67. Add Binary LeetCode Solution

In this guide, you will get 67. Add Binary LeetCode Solution with the best time and space complexity. The solution to Add Binary problem is provided in various programming languages like C++, Java, and Python. This will be helpful for you if you are preparing for placements, hackathons, interviews, or practice purposes. The solutions provided here are very easy to follow and include detailed explanations.

Problem Statement
Complexity Analysis
Add Binary solution in C++
Add Binary solution in Java
Add Binary solution in Python
Additional Resources

Problem Statement of Add Binary

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.

Complexity Analysis

Time Complexity: O(\max(|\texttt{a}|, |\texttt{b}|))
Space Complexity: O(\max(|\texttt{a}|, |\texttt{b}|))

67. Add Binary LeetCode Solution in C++

class Solution {
 public:
  string addBinary(string a, string b) {
    string ans;
    int carry = 0;
    int i = a.length() - 1;
    int j = b.length() - 1;

    while (i >= 0 || j >= 0 || carry) {
      if (i >= 0)
        carry += a[i--] - '0';
      if (j >= 0)
        carry += b[j--] - '0';
      ans += carry % 2 + '0';
      carry /= 2;
    }

    ranges::reverse(ans);
    return ans;
  }
};
/* code provided by PROGIEZ */

67. Add Binary LeetCode Solution in Java

class Solution {
  public String addBinary(String a, String b) {
    StringBuilder sb = new StringBuilder();
    int carry = 0;
    int i = a.length() - 1;
    int j = b.length() - 1;

    while (i >= 0 || j >= 0 || carry == 1) {
      if (i >= 0)
        carry += a.charAt(i--) - '0';
      if (j >= 0)
        carry += b.charAt(j--) - '0';
      sb.append(carry % 2);
      carry /= 2;
    }

    return sb.reverse().toString();
  }
}
// code provided by PROGIEZ

67. Add Binary LeetCode Solution in Python

class Solution:
  def addBinary(self, a: str, b: str) -> str:
    ans = []
    carry = 0
    i = len(a) - 1
    j = len(b) - 1

    while i >= 0 or j >= 0 or carry:
      if i >= 0:
        carry += int(a[i])
        i -= 1
      if j >= 0:
        carry += int(b[j])
        j -= 1
      ans.append(str(carry % 2))
      carry //= 2

    return ''.join(reversed(ans))
 # code by PROGIEZ