add two linked list as integer

最新推荐文章于 2024-08-05 18:40:52 发布

原创最新推荐文章于 2024-08-05 18:40:52 发布 · 637 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#list #integer #numbers #null #output #function

链表（linkedlist）专栏收录该内容

20 篇文章

订阅专栏

本文介绍了一种解决两个链表表示的大数相加问题的方法。通过使用两个栈来分别存储链表中的数字，实现从低位到高位逐位相加，并处理进位问题，最终将结果以链表形式返回。

Question:

You have two numbers represented by a linked list, where each node contains a single digit. Write a function that adds the two numbers and returns the sum as a linked list.

EXAMPLE:

input: (3 -> 1 -> 5), (5 -> 9 -> 2)

output: 9 -> 0 -> 7

Analyze:

use two stacks to store the numbers in the list, and then the last number of the lists will be on the top of the stacks, we pop the stack and add the numbers, and save the result into the linked list.

Code:

public static LinkedList addList(Node h1, Node h2) {
	//save the numbers in the list to stacks
	Stack<Node> s1 = new Stack<Node>();
	Stack<Node> s2 = new Stack<Node>();
	
	while(h1 != null) {
		s1.push(h1);
		h1 = h1.next;
	}
	while(h2 != null) {
		s2.push(h2);
		h2 = h2.next;
	}
	//LinkedList saves the result
	LinkedList list = new LinkedList();
	
	int sum = 0;
	int carry = 0;
	
	while(!s1.empty() && !s1.empty()) {
		sum = s1.pop().data + s2.pop().data + carry;
		carry = sum / 10;
		sum = sum % 10;
		list.addFirst(sum);
	}
	
	while(!s1.empty()) {
		sum = s1.pop().data + carry;
		carry = sum / 10;
		sum = sum % 10;
		list.addFirst(sum);
	}
	
	while(!s2.empty()) {
		sum = s1.pop().data + carry;
		carry = sum / 10;
		sum = sum % 10;
		list.addFirst(sum);
	}
	// don't forget the carry
	if (carry != 0) list.addFirst(carry);
	
	return list;
}

http://blog.youkuaiyun.com/beiyetengqing