Two numbers together

Given two non-empty list to represent two non-negative integers. The highest number of bits are located in the list starting position. They each node only stores a single digit. The two numbers together will return a new list.

 

You may assume that in addition to the numbers 0, these two figures will not begin with a zero.

Advanced:

If the input list can not be changed how to deal with? In other words, you can not flip nodes in the list.

Example:

Input: (7 -> 2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 8 -> 0 -> 7

Solution 1:

  

public  static  class ListNode {
     Private  int Val;
     Private ListNode Next; 

    public ListNode ( int Val) {
       the this .val = Val; 
    } 
  } 

  public  static ListNode addTwoNumbers (ListNode L1, L2 ListNode) {
     / * inverted list * / 
    ListNode R1 = Reverse (L1);
     / * inverted list * / 
    ListNode R2 = Reverse (L2);
     / * dummy node to define a new linked list * / 
    ListNode dumb = new new ListNode (0);
     / * Define a reference point to the dummy node * / 
    ListNode R & lt = dumb;
     / * addend * / 
    int the Add = 0 ;
     / * traversing two lists * / 
    the while (R1 =! Null || R2 =! Null ) {
       int Val = the Add; 
      the Add = 0 ;
       IF (! R1 = null ) { 
        Val = Val + r1.val; 
        R1 = r1.next; 
      } 
      IF (! R2 = null ) { 
        Val = Val + r2.val;
        r2 = r2.next;
      }
      if (val >= 10) {
        val = val - 10;
        add = 1;
      }
      dumb.next = new ListNode(val);
      dumb = dumb.next;
    }
    if (add > 0) {
      dumb.next = new ListNode(add);
    }
    /*翻转新链表*/
    return reverse(r.next);
  }

  public static ListNode reverse(ListNode head) {
    ListNode pre = null;
    while (head != null) {
      ListNode tmp = head.next;
      head.next = pre;
      pre = head;
      head = tmp;
    }
    return pre;
  }

View Code

 

Source: stay button (LeetCode)
link: https: //leetcode-cn.com/problems/add-two-numbers-ii