Leetcode#67 Add Binary

原题地址

简单模拟题

代码：

string addBinary(string a, string b) {
        int i = a.length() - 1;
        int j = b.length() - 1;
        int carry = 0;
        string sum;
        
        while (i >= 0 && j >= 0) {
            sum += ((a[i] - '0') + (b[j] - '0') + carry) % 2 + '0';
            carry = ((a[i] - '0') + (b[j] - '0') + carry) / 2;
            i--;
            j--;
        }
        
        while (i >= 0) {
            sum += ((a[i] - '0') + carry) % 2 + '0';
            carry = ((a[i] - '0') + carry) / 2;
            i--;
        }
        
        while (j >= 0) {
            sum += ((b[j] - '0') + carry) % 2 + '0';
            carry = ((b[j] - '0') + carry) / 2;
            j--;
        }
        
        if (carry > 0)
            sum += '1';
        
        i = 0;
        while (i * 2 < sum.length()) {
            swap(sum[i], sum[sum.length() - 1 - i]);
            i++;
        }
        
        return sum;
}