[LeetCode 67] Add Binary

Given two binary strings, return their sum (also a binary string).

For example,

a = "11" b = "1" Return "100".

Diffculty
Easy

Similar Problems
[LeetCode ] Add Two Numbers Medium [LeetCode ] Multiply Strings Medium [LeetCode ] Plus One Medium

Analysis

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

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

    if (carry > 0) result.push_back(carry + '0');
    reverse(result.begin(), result.end());

    return result;
}

};