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use super::Solution;
/******************** provided code ********************/
#[derive(PartialEq, Eq, Clone, Debug)]
pub struct ListNode {
pub val: i32,
pub next: Option<Box<ListNode>>,
}
impl ListNode {
#[inline]
fn new(val: i32) -> Self {
ListNode { next: None, val }
}
}
/******************** my code ********************/
use std::ptr::NonNull;
struct List {
head: Option<Box<ListNode>>,
tail: Option<NonNull<Box<ListNode>>>,
}
impl List {
fn new() -> List {
List {
head: None,
tail: None,
}
}
fn append(&mut self, val: i32) {
let node = Some(Box::new(ListNode::new(val)));
unsafe {
match self.tail {
None => {
self.head = node;
self.tail = Some(NonNull::from(self.head.as_mut().unwrap()));
}
Some(mut t) => {
let last_node = t.as_mut();
last_node.next = node;
self.tail = Some(NonNull::from(last_node.next.as_mut().unwrap()));
}
}
}
}
fn to_result(self) -> Option<Box<ListNode>> {
self.head
}
}
impl Solution {
pub fn add_two_numbers(
l1: Option<Box<ListNode>>,
l2: Option<Box<ListNode>>,
) -> Option<Box<ListNode>> {
let mut l1 = l1;
let mut l2 = l2;
let mut result = List::new();
let mut carry = false;
loop {
match l1 {
None => {
while let Some(v) = l2 {
let digit = v.val + if carry { 1 } else { 0 };
carry = digit > 9;
let digit = digit % 10;
result.append(digit);
l2 = v.next;
}
break;
}
Some(v1) => match l2 {
None => {
let digit = v1.val + if carry { 1 } else { 0 };
carry = digit > 9;
let digit = digit % 10;
result.append(digit);
l1 = v1.next;
while let Some(v) = l1 {
let digit = v.val + if carry { 1 } else { 0 };
carry = digit > 9;
let digit = digit % 10;
result.append(digit);
l1 = v.next;
}
break;
}
Some(v2) => {
let digit = v1.val + v2.val + if carry { 1 } else { 0 };
carry = digit > 9;
let digit = digit % 10;
result.append(digit);
l1 = v1.next;
l2 = v2.next;
}
},
}
}
if carry {
result.append(1);
}
return result.to_result();
}
}
#[cfg(test)]
mod test {
use super::{List, ListNode, Solution};
trait IntoList {
fn into_list(self) -> Option<Box<ListNode>>;
}
trait IntoVec {
fn into_vec(self) -> Vec<i32>;
}
impl IntoList for Vec<i32> {
fn into_list(self) -> Option<Box<ListNode>> {
let mut list = List::new();
for i in self {
list.append(i);
}
list.to_result()
}
}
impl IntoVec for Option<Box<ListNode>> {
fn into_vec(self) -> Vec<i32> {
let mut result = Vec::new();
let mut node = self;
while let Some(v) = node {
result.push(v.val);
node = v.next;
}
result
}
}
#[test]
fn test() {
assert_eq!(
Solution::add_two_numbers(vec![2, 4, 3].into_list(), vec![5, 6, 4].into_list())
.into_vec(),
vec![7, 0, 8]
);
assert_eq!(
Solution::add_two_numbers(vec![9, 9, 9].into_list(), vec![1].into_list()).into_vec(),
vec![0, 0, 0, 1]
);
}
}
|
