README.md

1673. Find the Most Competitive Subsequence

Given an integer array nums and a positive integer k, return the most competitive subsequence of nums of size k.

An array's subsequence is a resulting sequence obtained by erasing some (possibly zero) elements from the array.

We define that a subsequence a is more competitive than a subsequence b (of the same length) if in the first position where a and b differ, subsequence a has a number less than the corresponding number in b. For example, [1,3,4] is more competitive than [1,3,5] because the first position they differ is at the final number, and 4 is less than 5.

Example 1:

Input: nums = [3,5,2,6], k = 2
Output: [2,6]
Explanation: Among the set of every possible subsequence: {[3,5], [3,2], [3,6], [5,2], [5,6], [2,6]}, [2,6] is the most competitive.

Example 2:

Input: nums = [2,4,3,3,5,4,9,6], k = 4
Output: [2,3,3,4]

Constraints:

• 1 <= nums.length <= 105
• 0 <= nums[i] <= 109
• 1 <= k <= nums.length

Solutions (Rust)

1. Solution

impl Solution {
    pub fn most_competitive(nums: Vec<i32>, k: i32) -> Vec<i32> {
        let k = k as usize;
        let mut ret = vec![];

        for i in 0..nums.len() {
            while let Some(&num) = ret.last() {
                if num > nums[i] && k - ret.len() < nums.len() - i {
                    ret.pop();
                } else {
                    break;
                }
            }

            if ret.len() < k {
                ret.push(nums[i]);
            }
        }

        ret
    }
}