add RemoveDuplicatesfromSortedArray2

Medium/RemoveDuplicatesfromSortedArray2.java

@@ -0,0 +1,43 @@
+/**
+ * Remove Duplicates from Sorted Array II
+ * Follow up for "Remove Duplicates":
+ * What if duplicates are allowed at most twice?
+ * For example,
+ * Given sorted array nums = [1,1,1,2,2,3],
+ * Your function should return length = 5, with the first five elements of nums being 1, 1, 2, 2 and 3. It doesn't matter what you leave beyond the new length.
+ * Note: create a countEach variable to count duplicated times for each integer in array.
+ * Time complexity = O(n) 
+ * @author chenshuna
+ */
+
+public class RemoveDuplicatesfromSortedArray2 {	
+    public static int removeDuplicates(int[] nums) {
+        int res = 1;
+        if(nums.length <= 1){
+            return nums.length;
+        }
+        int countEach = 1;
+        for(int i = 1; i<nums.length; i++){
+            if(nums[i] == nums[i-1] && countEach < 2){
+                nums[res] = nums[i];
+                countEach++;
+                res++;
+            }
+            else if(nums[i] != nums[i-1]){
+                nums[res] = nums[i];
+                res++;
+                countEach = 1;
+            }
+            else{
+                countEach++;
+            }
+        }
+        return res;
+    }
+
+	public static void main(String[] args) {
+		// TODO Auto-generated method stub
+		int[] res = {1,1,1,2,3};
+		System.out.print(removeDuplicates(res));
+	}
+}