思路:
语法注意:
(1)HashSet
的 contains
方法期望引用 &T
而不是值类型 T
,主要是为了避免不必要的内存拷贝和移动,同时遵循 Rust 的所有权和借用规则
(2)在 for num in &
HashSet
比在 for &num in &Vec
中遍历 快 20 倍。
代码:
use std::collections::*;
impl Solution {
pub fn longest_consecutive(nums: Vec<i32>) -> i32 {
let mut set = HashSet::new();
for &num in &nums {
set.insert(num);
}
let mut longest = 0;
for num in &set {
if set.contains(&(*num - 1)) {continue;}
let mut temp = *num + 1;
while set.contains(&(temp)) {
temp += 1;
}
longest = longest.max(temp - *num);
}
longest
}
}