LeetCode in Net
67. Add Binary
Easy
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 <= 104aandbconsist only of'0'or'1'characters.- Each string does not contain leading zeros except for the zero itself.
Solution
public class Solution {
public string AddBinary(string a, string b) {
var sb = new System.Text.StringBuilder();
int i = a.Length - 1;
int j = b.Length - 1;
int carry = 0;
while (i >= 0 || j >= 0 || carry > 0) {
int sum = carry;
if (i >= 0) {
sum += a[i--] - '0';
}
if (j >= 0) {
sum += b[j--] - '0';
}
sb.Insert(0, (char)('0' + (sum % 2)));
carry = sum / 2;
}
return sb.ToString();
}
}