Remove Duplicates from Sorted Array II

public class RemoveDuplicatesfromSortedArrayII {
public int removeDuplicates(int[] nums) {
if (nums.length<=0) return 0;
int res = 0,flag = 0,tem = nums[0];
for (int i=0;i<nums.length;i++){
if (nums[i]==tem&&flag<=1){
nums[res++] = nums[i];
flag++;
}else if (nums[i]!=tem){
flag = 1;
tem = nums[i];
nums[res++] = nums[i];
}else if (flag>=2&&nums[i]==tem){
continue;
}else{
flag = 0;
}
}
return res;
}
}