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 <= 1050 <= nums[i] <= 1091 <= k <= nums.lengthstruct Solution;
impl Solution {
fn most_competitive(nums: Vec<i32>, k: i32) -> Vec<i32> {
let n = nums.len();
let k = k as usize;
let mut arr = vec![];
let mut m = 0;
for i in 0..n {
while let Some(&top) = arr.last() {
if top > nums[i] && k < n - m {
m += 1;
arr.pop();
} else {
break;
}
}
arr.push(nums[i]);
}
arr[0..k].to_vec()
}
}
#[test]
fn test() {
let nums = vec![3, 5, 2, 6];
let k = 2;
let res = vec![2, 6];
assert_eq!(Solution::most_competitive(nums, k), res);
let nums = vec![2, 4, 3, 3, 5, 4, 9, 6];
let k = 4;
let res = vec![2, 3, 3, 4];
assert_eq!(Solution::most_competitive(nums, k), res);
}