Given a sorted array nums, 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 by modifying the input array in-place with O(1) extra memory.
和之前MoveZeroToEnd很像，只需记录重复的次数及需要replace即可

Solution

class Solution {
    public int removeDuplicates(int[] nums) {
        int moveCount=0;
        for(int i =0;i<nums.length-1;i++){
            if(nums[i]==nums[i+1]){
                moveCount+=1;
            }
            else{
                replace(nums,i+1,i+1-moveCount);
                      
            }
        }
        return nums.length-moveCount;
    }
    public void repalce(int[] nums,int i,int j){
        // int tmp=nums[i];
        // nums[i]=nums[j];
        nums[j]=nums[i];
    }
}