LeetCode in Kotlin

2576. Find the Maximum Number of Marked Indices

Medium

You are given a 0-indexed integer array nums.

Initially, all of the indices are unmarked. You are allowed to make this operation any number of times:

• Pick two different unmarked indices i and j such that 2 * nums[i] <= nums[j], then mark i and j.

Return the maximum possible number of marked indices in nums using the above operation any number of times.

Example 1:

Input: nums = [3,5,2,4]

Output: 2

Explanation: In the first operation: pick i = 2 and j = 1, the operation is allowed because 2 * nums[2] <= nums[1]. Then mark index 2 and 1. It can be shown that there’s no other valid operation so the answer is 2.

Example 2:

Input: nums = [9,2,5,4]

Output: 4

Explanation: In the first operation: pick i = 3 and j = 0, the operation is allowed because 2 * nums[3] <= nums[0].

Then mark index 3 and 0.

In the second operation: pick i = 1 and j = 2, the operation is allowed because 2 * nums[1] <= nums[2]. Then mark index 1 and 2.

Since there is no other operation, the answer is 4.

Example 3:

Input: nums = [7,6,8]

Output: 0

Explanation: There is no valid operation to do, so the answer is 0.

Constraints:

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

Solution

class Solution {
    fun maxNumOfMarkedIndices(nums: IntArray): Int {
        nums.sort()
        var count = 0
        var i = 0
        var j = nums.size / 2

        while (j < nums.size && i < nums.size / 2) {
            if (nums[i] * 2 <= nums[j]) {
                count += 2
                i++
                j++
            } else {
                j++
            }
        }

        return count
    }
}

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