两数相加JavaScript

深碍√TFBOYSˉ_ 2022-05-19 04:29 137阅读 0赞

两数相加题目详情：[https://leetcode-cn.com/problems/add-two-numbers/description/][https_leetcode-cn.com_problems_add-two-numbers_description]

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对博主而言，这道题可能更侧重JavaScript如何去实现链表的操作。不过leetcode题解注释中已经指明了链表的方式。  
参考博客如下：[http://www.liuyiqi.cn/2017/03/12/add-two-numbers/][http_www.liuyiqi.cn_2017_03_12_add-two-numbers]

/** * Definition for singly-linked list. * function ListNode(val) { * this.val = val; * this.next = null; * } */
    /** * @param {ListNode} l1 * @param {ListNode} l2 * @return {ListNode} */
    var addTwoNumbers = function(l1, l2) {
        //carry为进位，初始化为0 
        var c1 = l1, c2 = l2, c3, l3, carry = 0;
    
        while(c1 || c2 || carry) {
            var v1 = 0, v2 = 0;
    
            if(c1) {
                //根据前文给出的代码结构val、next
                v1 = c1.val;
                c1 = c1.next;
            }
    
            if (c2) {
                v2 = c2.val;
                c2 = c2.next;
            }
    
            var sum = v1 + v2 + carry;
            carry = Math.floor(sum / 10);//得到进位
    
            if(!c3) {
                l3 = new ListNode(sum % 10);
                c3 = l3;
            } else {
                c3.next = new ListNode(sum % 10);
                c3 = c3.next;
            }
        }
        return l3;
    
    };

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**总结：**这道题的思路本身也不太难，主要考察的是对链表的操作，要理解链表的组成方式，增删查的方式。另一个就是按位进行加法计算，需要考虑进位（数a+数b+进位cin，返回数c和新的进位cin）。  
因为链表和按位加法都还算的上有一点基础，但用JavaScript写以及其对链表的操作委实不熟，所以查阅了一些js链表的博客。推荐如下：  
[https://juejin.im/entry/59cb70995188256aa423b680][https_juejin.im_entry_59cb70995188256aa423b680]  
[http://web.jobbole.com/88843/][http_web.jobbole.com_88843]

[https_leetcode-cn.com_problems_add-two-numbers_description]: https://leetcode-cn.com/problems/add-two-numbers/description/
[http_www.liuyiqi.cn_2017_03_12_add-two-numbers]: http://www.liuyiqi.cn/2017/03/12/add-two-numbers/
[https_juejin.im_entry_59cb70995188256aa423b680]: https://juejin.im/entry/59cb70995188256aa423b680
[http_web.jobbole.com_88843]: http://web.jobbole.com/88843/