class Solution {
public:
int removeDuplicates(vector<int> &nums) {

if(nums.empty())
{
return 0;
}

int n = nums.size(),k=0;

for(int i=1;i<n;++i)
{
if(nums[i] != nums[k])
{
nums[++k] = nums[i];
}
}
nums.resize(k+1);
return k+1;
}
};