remove-duplicates-from-sorted-array-ii.md

Code

func removeDuplicates(nums []int) int {
	if len(nums) <= 1 {
		return 1
	}

	i := 0
	for _, n := range nums {
		if i < 2 || n > nums[i-2] {
			nums[i] = n
			i += 1
		}
	}

	return i
}

Solution in mind

• Keep a pointer to index i. Iterate through array nums, using each element num in nums.

• Since a number can occur at most twice, check if the current number is greater than the number at i-2.

• If it is, place the number at i and move i forward by 1 place.

• If not, iterate to the next number and check if can be placed at i by checking if it is greater than the number at i-2.