remove-duplicates-from-sorted-array.md

Code

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

	slow := 0
	fast := 1
	n := len(nums)

	for fast < n {
		if nums[fast] == nums[slow] {
			fast++
		} else {
			slow++
			nums[slow] = nums[fast]
		}
	}

	return slow + 1
}

Solution in mind

• Make use of 2 pointers, a fast and slow moving pointer. Initialise fast to 1 and slow to 0.

• While fast has not reached the end of array, check if the elements at index fast and slow are same, if yes, move fast forward by 1 place.

• If not, copy the non duplicate element into the position after slow.

• Once fast reaches the end of array, all unique elements will be stored inside the first "slow" number of elements in the array.