LeetCode:Remove Duplicates from Sorted Array I&&II

class Solution {
public:

int removeDuplicates(int A[], int n) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
if(n==0) return 0;
int length = 1;
for(int i = 1;i<n;i++)
if(A[i]!=A[i-1])
length++;
int p=0;
for(int i = 0;i<length;i++)
{
int val = A[p];
A[i] = val;

while(A[p]==val)
{
p++;

}

}
return length;

}
};

class Solution {
public:
int removeDuplicates(int A[], int n) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
if(n<=2) return n;
int length = 2;
for(int i =2;i<n;i++)
if(A[i]!=A[i-1]||A[i]!=A[i-2])
length++;
int p = 0;
for(int i =0;i<length;i++)
{
while(p+2<n&&A[p]==A[p+1]&&A[p]==A[p+2])
{
p++;
}
A[i]= A[p];
p++;
}
return length;
}
};