Leetcode -- Remove Duplicates from Sorted Array II

 class Solution {  
 public:  
   int removeDuplicates(int A[], int n) {  
       if(n <=2) {  
     return n;  
    }  
     int last = 1;  
    int curr = 2;  
    while(curr < n) {  
     if(A[curr] == A[last] && A[curr] == A[last - 1]) {  
      curr++;  
     } else {  
      last++;  
      A[last] = A[curr];  
      curr++;  
     }  
    }  
    return last + 1;  
   }  
 };