Решение

class Solution {
    fun removeDuplicates(nums: IntArray): Int {
        val n = nums.size
        if (n == 0) return 0
        var w = 1
        var i = 1
        var last = nums[0]
        while (i < n) {
            val v = nums[i]
            if (v != last) {
                nums[w++] = v
                last = v
            }
            i++
        }
        return w
    }
}