算法题-不用算术运算符实现两个数的加法

分手后的思念是犯贱 2022-01-26 01:45 356阅读 0赞

先了解异或和与运算：

0和1的异或运算如下：`0^0 = 0， 1^0 = 1， 0^1 = 1，1^1 = 0`

再看看与运算：`0&0=0; 0&1=0; 1&0=0; 1&1=1;`

那么加法运算可以这样实现：

1）先不考虑进位，按位计算各位累加（用异或实现），得到a;

2）然后计算进位，并将进位的值左移，得到值b。若b为0，则a就是加法运算的结果；若b不为0，则a+b即得结果（递归调用这个过程）。

function bitAdd(a,b){
    	if(b==0){
    		return a;
    	}
    	var sum = a^b;
    	var carry = (a&b)<<1;
    	return bitAdd(sum,carry);
    }
    
    bitAdd(5,7)
    12

参考文章：  
[https://blog.csdn.net/g6U8W7p06dCO99fQ3/article/details/79227169][https_blog.csdn.net_g6U8W7p06dCO99fQ3_article_details_79227169]  
[https://www.cnblogs.com/houjun/p/4908725.html][https_www.cnblogs.com_houjun_p_4908725.html]

[https://blog.csdn.net/u013793732/article/details/79506927][https_blog.csdn.net_u013793732_article_details_79506927]  
[https://www.cnblogs.com/newpanderking/p/3925056.html][https_www.cnblogs.com_newpanderking_p_3925056.html]  
[https://brokendreams.iteye.com/blog/2084088][https_brokendreams.iteye.com_blog_2084088]  
[https://blog.csdn.net/qq\_38148754/article/details/82315531][https_blog.csdn.net_qq_38148754_article_details_82315531]

[https_blog.csdn.net_g6U8W7p06dCO99fQ3_article_details_79227169]: https://blog.csdn.net/g6U8W7p06dCO99fQ3/article/details/79227169
[https_www.cnblogs.com_houjun_p_4908725.html]: https://www.cnblogs.com/houjun/p/4908725.html
[https_blog.csdn.net_u013793732_article_details_79506927]: https://blog.csdn.net/u013793732/article/details/79506927
[https_www.cnblogs.com_newpanderking_p_3925056.html]: https://www.cnblogs.com/newpanderking/p/3925056.html
[https_brokendreams.iteye.com_blog_2084088]: https://brokendreams.iteye.com/blog/2084088
[https_blog.csdn.net_qq_38148754_article_details_82315531]: https://blog.csdn.net/qq_38148754/article/details/82315531