struct Solution;
use std::collections::HashMap;
impl Solution {
fn is_possible(nums: Vec<i32>) -> bool {
let mut left: HashMap<i32, usize> = HashMap::new();
let mut end: HashMap<i32, usize> = HashMap::new();
for &x in &nums {
*left.entry(x).or_default() += 1;
}
for &x in &nums {
if *left.entry(x).or_default() == 0 {
continue;
}
if *end.entry(x - 1).or_default() > 0 {
*left.entry(x).or_default() -= 1;
*end.entry(x - 1).or_default() -= 1;
*end.entry(x).or_default() += 1;
continue;
}
if *left.entry(x + 1).or_default() > 0 && *left.entry(x + 2).or_default() > 0 {
*left.entry(x).or_default() -= 1;
*left.entry(x + 1).or_default() -= 1;
*left.entry(x + 2).or_default() -= 1;
*end.entry(x + 2).or_default() += 1;
continue;
}
return false;
}
true
}
}
#[test]
fn test() {
let nums = vec![1, 2, 3, 3, 4, 5];
let res = true;
assert_eq!(Solution::is_possible(nums), res);
let nums = vec![1, 2, 3, 3, 4, 4, 5, 5];
let res = true;
assert_eq!(Solution::is_possible(nums), res);
let nums = vec![1, 2, 3, 4, 4, 5];
let res = false;
assert_eq!(Solution::is_possible(nums), res);
}