Add Binary <leetcode>

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

For example,
a = "11"
b = "1"
Return "100".

 

算法：模拟加法过程

class Solution {
public:
    string addBinary(string a, string b) {
        int  len1=a.size();
        int  len2=b.size();
        int c=0;
        reverse(a.begin(),a.end());
        reverse(b.begin(),b.end());
        string s="";
        int len=max(len1,len2);
        for(int i=0;i<len;i++)
        {
            int t=0;
            if(i<len1)  t+=a[i]-'0';
            if(i<len2)  t+=b[i]-'0';
            t+=c;
            c=t/2;
            s=(char)(t%2+'0')+s;
        }
        if(c>0) s=(char)(c+'0')+s;
        return s;
    }
};