We are given head, the head node of a linked list containing unique integer values.
We are also given the list G, a subset of the values in the linked list.
Return the number of connected components in G, where two values are connected if they appear consecutively in the linked list.
Example 1:
Input: head: 0->1->2->3 G = [0, 1, 3] Output: 2 Explanation: 0 and 1 are connected, so [0, 1] and [3] are the two connected components.
Example 2:
Input: head: 0->1->2->3->4 G = [0, 3, 1, 4] Output: 2 Explanation: 0 and 1 are connected, 3 and 4 are connected, so [0, 1] and [3, 4] are the two connected components.
Note:
N is the length of the linked list given by head, 1 <= N <= 10000. [0, N - 1].1 <= G.length <= 10000.G is a subset of all values in the linked list.struct Solution;
use rustgym_util::*;
use std::collections::HashSet;
use std::iter::FromIterator;
impl Solution {
fn num_components(head: ListLink, g: Vec<i32>) -> i32 {
let mut p = head;
let hs: HashSet<i32> = HashSet::from_iter(g);
let mut open = false;
let mut res = 0;
while let Some(node) = p {
if hs.contains(&node.val) {
if !open {
open = true;
}
} else {
if open {
open = false;
res += 1;
}
}
p = node.next;
}
if open {
res += 1;
}
res
}
}
#[test]
fn test() {
let head = list!(0, 1, 2, 3);
let g = vec![0, 1, 3];
let res = 2;
assert_eq!(Solution::num_components(head, g), res);
let head = list!(0, 1, 2, 3, 4);
let g = vec![0, 3, 1, 4];
let res = 2;
assert_eq!(Solution::num_components(head, g), res);
}