两个链表生成相加链表

/*
 * function ListNode(x){
 *   this.val = x;
 *   this.next = null;
 * }
 */

/**
 * 
 * @param head1 ListNode类 
 * @param head2 ListNode类 
 * @return ListNode类
 */
function addInList( head1 ,  head2 ) {
    // write code here
   let str1 = ‘‘; 
   let str2 = ‘‘;
    let count1 = 0;
    let count2 = 0;
    while(head1){
        str1 += head1.val;
        head1 = head1.next;
        count1++;
    }
    while(head2){
        str2 += head2.val;
        head2 = head2.next;
        count2++;
    }
    let max = count1 > count2 ? count1: count2;
    str1 = str1.padStart(max,‘0‘)
    str2 = str2.padStart(max,‘0‘)
    let f = 0 //进位
    let cur = ‘‘ //暂存值
    for(let i = max-1;i>=0;i--){
        let tmp = Number(str1[i])+Number(str2[i]) + f;
        f = Math.floor(tmp / 10);
        cur = tmp % 10 + cur;
    }
    // 最后一位是否进位
    cur = f ? `1${cur}` : cur;
    var curs = new ListNode(-1);
    var dummy = curs;
    for(let i = 0;i<cur.length;i++){
        var temp = new ListNode(cur[i]);
        dummy.next = temp;
        dummy = temp;
    }
    return curs.next;
}
// //翻转链表操作
// function reverseList(head){
//     var pre = null
//     var low = null
//     while(head){
//         low = head.next;
//         head.next = pre;
//         pre = head;
//         head = low;
//     }
//     return pre;
// }

module.exports = {
    addInList : addInList
};