26. 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.

For example,
Given input array nums = [1,1,2],

Your function should return length = 2, with the first two elements of nums being 1 and 2 respectively. It doesn't matter what you leave beyond the new length.

给定一个有序数组，删除重复元素，返回新的长度

C++（32ms）：

class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
        int res = 1 ;
        int len = nums.size() ;
        if (len < 1)
            return 0 ;
        for (int i = 0 ; i< len-1 ; i++){
            if (nums[i] != nums[i+1]){
                nums[res] = nums[i+1] ;
                res++ ;
            }
        }
        return res ;
    }
};

java(14ms):

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