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 A = [1,1,2],

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

思路：从头开始遍历，遍历一遍，即可

#include <iostream>
#include <vector>
using namespace std;
/*
在一个排好序的数组中删除重复的元素 并返回长度 
*/
int RemoveDuplicate(vector<int>& vec)
{
	if(vec.size()<=1)
		return vec.size();
	int i=0,j;
	for(j=1;j<vec.size();j++)
		if(vec[j] != vec[j-1])
		{
			i++;
			vec[i] = vec[j];
		}
	return i+1;
}


int main()
{
	int array[]={1,1,1,1,2,2,3,4,4,5,6,7};
	vector<int> vec(array,array+sizeof(array)/sizeof(int));
	cout<<RemoveDuplicate(vec);
	return 0;
}