[LeetCode] Array - Remove Duplicates from Sorted Array !!

 

Two Pointer로 구현

class Solution {
    public int removeDuplicates(int[] nums) {
        int i = 0;
		if(nums.length == 0) return 0;
		
		for (int j = i+1; j < nums.length; j++) {
			if(nums[i] != nums[j]) {
				i++;
				nums[i] = nums[j];
				
			}
		}		
		return i+1;
    }
}

 

 

O(N^2)

class Solution {
    public int removeDuplicates(int[] nums) {
        
        // The initial length is simply the capacity.
        int length = nums.length;
        
        // Assume the last element is always unique.
        // Then for each element, delete it iff it is
        // the same as the one after it. Use our deletion
        // algorithm for deleting from any index.
        for (int i = length - 2; i >= 0; i--) {
            if (nums[i] == nums[i + 1]) {
                // Delete the element at index i, using our standard
                // deletion algorithm we learned.
                for (int j = i + 1; j < length; j++) {
                    nums[j - 1] = nums[j];
                }
                // Reduce the length by 1.
                length--;
            }
        }
        // Return the new length.
        return length;
    }
}