123 lines
3.3 KiB
Rust
123 lines
3.3 KiB
Rust
/**
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* [2] Add Two Numbers
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*
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* You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order, and each of their nodes contains a single digit. Add the two numbers and return the sum as a linked list.
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* You may assume the two numbers do not contain any leading zero, except the number 0 itself.
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*
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* <strong class="example">Example 1:
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* <img alt="" src="https://assets.leetcode.com/uploads/2020/10/02/addtwonumber1.jpg" style="width: 483px; height: 342px;" />
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* Input: l1 = [2,4,3], l2 = [5,6,4]
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* Output: [7,0,8]
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* Explanation: 342 + 465 = 807.
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*
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* <strong class="example">Example 2:
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*
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* Input: l1 = [0], l2 = [0]
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* Output: [0]
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*
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* <strong class="example">Example 3:
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*
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* Input: l1 = [9,9,9,9,9,9,9], l2 = [9,9,9,9]
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* Output: [8,9,9,9,0,0,0,1]
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*
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*
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* Constraints:
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*
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* The number of nodes in each linked list is in the range [1, 100].
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* 0 <= Node.val <= 9
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* It is guaranteed that the list represents a number that does not have leading zeros.
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*
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*/
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pub struct Solution {}
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use crate::util::linked_list::{ListNode, to_list};
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// problem: https://leetcode.cn/problems/add-two-numbers/
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// discuss: https://leetcode.cn/problems/add-two-numbers/discuss/?currentPage=1&orderBy=most_votes&query=
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// submission codes start here
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// Definition for singly-linked list.
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// #[derive(PartialEq, Eq, Clone, Debug)]
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// pub struct ListNode {
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// pub val: i32,
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// pub next: Option<Box<ListNode>>
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// }
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//
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// impl ListNode {
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// #[inline]
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// fn new(val: i32) -> Self {
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// ListNode {
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// next: None,
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// val
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// }
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// }
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// }
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impl Solution {
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pub fn add_two_numbers(l1: Option<Box<ListNode>>, l2: Option<Box<ListNode>>)
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-> Option<Box<ListNode>> {
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let (mut left, mut right) = (l1, l2);
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let mut dummy_head = Some(Box::new(ListNode::new(0)));
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let mut now = &mut dummy_head;
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let mut overflow = 0;
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loop {
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if left.is_none() && right.is_none() && overflow == 0 {
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break
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}
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let left_value = match left {
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None => {
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0
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}
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Some(node) => {
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left = node.next;
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node.val
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}
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};
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let right_value = match right {
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None => {
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0
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}
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Some(node) => {
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right = node.next;
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node.val
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}
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};
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let value = overflow + left_value + right_value;
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overflow = value / 10;
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now.as_mut().unwrap().next = Some(Box::new(ListNode::new(value % 10)));
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now = &mut now.as_mut().unwrap().next;
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}
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dummy_head.unwrap().next
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}
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}
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// submission codes end
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn test_2() {
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assert_eq!(
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Solution::add_two_numbers(to_list(vec![2, 4, 3]), to_list(vec![5, 6, 4])),
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to_list(vec![7, 0, 8])
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);
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assert_eq!(
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Solution::add_two_numbers(to_list(vec![9, 9, 9, 9]), to_list(vec![9, 9, 9, 9, 9, 9])),
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to_list(vec![8, 9, 9, 9, 0, 0, 1])
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);
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assert_eq!(
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Solution::add_two_numbers(to_list(vec![0]), to_list(vec![0])),
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to_list(vec![0])
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);
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}
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}
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