https://leetcode.com/problems/add-binary/
Given two binary strings, return their sum (also a binary string).
The input strings are both non-empty and contains only characters
1 or 0.
Example 1:
Input: a = "11", b = "1" Output: "100"
Example 2:
Input: a = "1010", b = "1011" Output: "10101"https://leetcode.com/problems/add-binary/discuss/24488/Short-AC-solution-in-Java-with-explanation
public String addBinary(String a, String b) {
StringBuilder sb = new StringBuilder();
int i = a.length() - 1, j = b.length() -1, carry = 0;
while (i >= 0 || j >= 0) {
int sum = carry;
if (j >= 0) sum += b.charAt(j--) - '0';
if (i >= 0) sum += a.charAt(i--) - '0';
sb.append(sum % 2);
carry = sum / 2;
}
if (carry != 0) sb.append(carry);
return sb.reverse().toString();
}
Computation from string usually can be simplified by using a carry as such.
