problem_26.java

/*
26. Remove Duplicates from Sorted Array
Given an integer array nums sorted in non-decreasing order, remove the duplicates in-place such that each unique element appears only once. The relative order of the elements should be kept the same.
Consider the number of unique elements in nums to be k​​​​​​​​​​​​​​. After removing duplicates, return the number of unique elements k.
The first k elements of nums should contain the unique numbers in sorted order. The remaining elements beyond index k - 1 can be ignored. */

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

        return i + 1;
    }
}