solve problem Remove Duplicates From Sorted Array II

Author: P-ppc

README.md

@@ -130,6 +130,7 @@ All solutions will be accepted!
 |796|[Rotate String](https://leetcode-cn.com/problems/rotate-string/description/)|[java/py/js](./algorithms/RotateString)|Easy|
 |844|[Backspace String Compare](https://leetcode-cn.com/problems/backspace-string-compare/description/)|[java/py/js](./algorithms/BackspaceStringCompare)|Easy|
 |26|[Remove Duplicates From Sorted Array](https://leetcode-cn.com/problems/remove-duplicates-from-sorted-array/description/)|[java/py/js](./algorithms/RemoveDuplicatesFromSortedArray)|Easy|
+|80|[Remove Duplicates From Sorted Array II](https://leetcode-cn.com/problems/remove-duplicates-from-sorted-array-ii/description/)|[java/py/js](./algorithms/RemoveDuplicatesFromSortedArrayII)|Medium|
 |112|[Path Sum](https://leetcode-cn.com/problems/path-sum/description/)|[java/py/js](./algorithms/PathSum)|Easy|
 |113|[Path Sum II](https://leetcode-cn.com/problems/path-sum-ii/description/)|[java/py/js](./algorithms/PathSumII)|Medium|
 |437|[Path Sum III](https://leetcode-cn.com/problems/path-sum-iii/description/)|[java/py/js](./algorithms/PathSumIII)|Easy|

algorithms/RemoveDuplicatesFromSortedArrayII/README.md

@@ -0,0 +1,2 @@
+# Remove Duplicates From Sorted Array II
+We can solve this problem by double pointers

algorithms/RemoveDuplicatesFromSortedArrayII/Solution.java

@@ -0,0 +1,23 @@
+class Solution {
+    public int removeDuplicates(int[] nums) {
+        int length = nums.length;
+        if (length == 0)
+            return 0;
+
+        int count = 0,
+            pre = 0;
+
+        for (int i = 1; i < length; i++) {
+            if (nums[i] == nums[pre]) {
+                count++;
+                if (count < 2)
+                    nums[++pre] = nums[i];
+            } else {
+                nums[++pre] = nums[i];
+                count = 0;
+            }
+        }
+
+        return pre + 1;
+    }
+}

algorithms/RemoveDuplicatesFromSortedArrayII/solution.js

@@ -0,0 +1,25 @@
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var removeDuplicates = function(nums) {
+    let length = nums.length
+    if (length == 0)
+        return 0
+    
+    let count = 0,
+        pre = 0
+    
+    for (let i = 1; i < length; i++) {
+        if (nums[i] == nums[pre]) {
+            count++
+            if (count < 2)
+                nums[++pre] = nums[i]
+        } else {
+            nums[++pre] = nums[i]
+            count = 0
+        }
+    }
+    
+    return pre + 1
+};

algorithms/RemoveDuplicatesFromSortedArrayII/solution.py

@@ -0,0 +1,25 @@
+class Solution(object):
+    def removeDuplicates(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: int
+        """
+        if len(nums) == 0:
+            return 0
+        
+        count = 0
+        pre = 0
+        
+        for i in xrange(1, len(nums)):
+            if nums[pre] == nums[i]:
+                count += 1
+                if count < 2:
+                    pre += 1
+                    nums[pre] = nums[i]
+            else:
+                pre += 1
+                nums[pre] = nums[i]
+                count = 0
+        
+        return pre + 1
+