题解 | #11.链表相加(二)#

栈、链表

将两个链表从头逐个放到stack中

从两个stack中分别取出值进行相加操作，注意如果产生进位则放到下一次中，因此引入jinwei这个变量

注意，两个stack均为空后，还要再次判断一下是否有进位

function addInList( head1 ,  head2 ) {
  let stack1 = new Array();
  let stack2 = new Array();
  
  while(head1 != null){
    stack1.push(head1);
    head1 = head1.next;
  }
  while(head2 != null){
    stack2.push(head2);
    head2 = head2.next;
  }
  let jinwei = 0;//之前的进位
  let pHead = new ListNode(-1);
  let pre = pHead;
  while(stack1.length!=0 || stack2.length!=0){
    let node1 = stack1.pop();
    let node2 = stack2.pop();
    
    let val1 = node1 ? node1.val : 0;
    let val2 = node2 ? node2.val : 0;
    
    let falseValue = val1 + val2 + jinwei;
    let trueValue = falseValue % 10;
    jinwei = (falseValue - trueValue) / 10;
    let node = new ListNode(trueValue);
    node.next = pre.next;
    pre.next = node;
  }
  if(jinwei == 1){
    let temp = new ListNode(1);
    temp.next = pHead.next;
    pHead.next = temp;
  }
  return pHead.next;
}
module.exports = {
    addInList : addInList
};