Add Binary leetcode

最新推荐文章于 2018-09-23 20:59:58 发布

原创最新推荐文章于 2018-09-23 20:59:58 发布 · 650 阅读

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本文详细解析了如何将两个二进制字符串相加并返回结果字符串的方法，包括实现过程和优化策略。

Add Binary

Apr 2 '12

5763 / 16556

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

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

我的丑陋的

public class Solution {
    public String addBinary(String a, String b) {

        if(a==null||b==null) return null;
        
        int la = a.length(),lb = b.length();
        
        int add = 0;
        int i = la-1,j=lb-1;
        StringBuilder sb = new StringBuilder();
        while(i>=0 && j>=0){
            int sum =( a.charAt(i)-'0')
            +b.charAt(j)-'0'+add;
            
            add = sum/2;
            sum = sum%2;
            sb.insert(0,sum+"");
            i--;
            j--;
        }
        if(i>=0){
            j=i;
            b=a;
        }
        
        while(j>=0){
            int sum = b.charAt(j)-'0'+add;  //
            add = sum/2;
            sum = sum%2;
            sb.insert(0,sum+"");
            j--;
        }
        if(add>0){
            sb.insert(0,"1");  //
        }
        return sb.toString();
    }
}

别人的比较优美的写法

class Solution {
public:
    string addBinary(string a, string b) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        int la = a.size();
        int lb = b.size();
        string sum = la > lb ? a : b;
        int overflow = 0;
        for( int i = 0; i < sum.size(); i ++ )
        {
            char ca = i < la ? a[la - i - 1] : '0';
            char cb = i < lb ? b[lb - i - 1] : '0';
            int bit = ca - '0' + cb - '0' + overflow;
            overflow = bit / 2;
            sum[sum.size() - i - 1] = bit % 2 + '0';
        }
        if(overflow)
        {
            sum = "1" + sum;
        }
        return sum;
    }
};