[LeetCode]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.

class Solution {
public:
	int removeDuplicates(vector<int>& nums) {
		int count = 0;
		for (int i = 1; i < nums.size(); ++i) {
			if (nums[i] == nums[i - 1]) {
				++count;
			}
			else {
				nums[i - count] = nums[i];
			}
		}
		// 释放多余空间，题目没要求释放,可加可不加
		//nums.erase(nums.end() - count, nums.end());  
		return nums.size();
	}
};

或者如下：

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