67. Add Binary（js）

67. 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"
题意：给定两个二进制数的字符串，求这两个二进制数相加，并返回求和数字的二进制
代码如下：

/**
 * @param {string} a
 * @param {string} b
 * @return {string}
 */
var addBinary = function(a, b) {
            var aLen=a.length-1;
        var bLen=b.length-1;
        var c=0;
        var s="";
        while(aLen >=0 || bLen >=0 || c===1){
            c+=aLen>=0 ? parseInt(a[aLen--]):0;
            c+=bLen>=0 ? parseInt(b[bLen--]):0;

            s=(c%2)+s;
            c=parseInt(c/2)
        }
        return s;
};