Degree of an array

Array Hash Table

58.2% acceptance

Feb 20, 2026

3261

1810

Given a non-empty array of non-negative integers nums, find the smallest length subarray with the same degree as nums.

Solution

Rust

Time O(n)

Space O(n)

LeetCode

solution.rs

use std::collections::HashMap;
impl Solution {
  pub fn find_shortest_sub_array(nums: Vec<i32>) -> i32 {
    let mut count: HashMap<i32, i32> = HashMap::new();
    let mut first: HashMap<i32, usize> = HashMap::new();
    let mut last: HashMap<i32, usize> = HashMap::new();
    for (i, &n) in nums.iter().enumerate() {
      *count.entry(n).or_insert(0) += 1;
      first.entry(n).or_insert(i);
      last.insert(n, i);
    }
    let degree = *count.values().max().unwrap();
    count.iter()
      .filter(|&(_, &c)| c == degree)
      .map(|(&n, _)| (last[&n] - first[&n] + 1) as i32)
      .min()
      .unwrap()
  }
}