[Lintcode]Remove Duplicates from Sorted Array

Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length.

Do not allocate extra space for another array, you must do this in place with constant memory.

Example

Given input array A = [1,1,2],

Your function should return length = 2, and A is now [1,2].

双指针。遇到重复的值跳过。

public class Solution {
    /**
     * @param A: a array of integers
     * @return : return an integer
     */
    public int removeDuplicates(int[] nums) {
        if(nums.length == 0) return 0;
        
        int index = 0;
        for(int i = index + 1; i < nums.length; i++) {
            if(nums[index] != nums[i]) {
                nums[index + 1] = nums[i];
                index++;
            }
        }
        return index + 1;
    }
}