#include <iostream>
using namespace std;
int removeDuplicates(int A[], int n)//双指针思想,但还是wa了好多次,注意边界
{
if(n>=1)
{
int start = 0;
A[start]=A[0];
for(int i = 1; i < n; i++)
if (A[i-1]!= A[i])
{
A[++start] = A[i];
}
return start+1;
}
else
return 0;
}