feat: update cpp solution to lc problem: No.0026 (#700)

Author: Bernhard-L

solution/0000-0099/0026.Remove Duplicates from Sorted Array/README.md

@@ -120,6 +120,16 @@ public:
 };
 ```
 
+```cpp
+class Solution {
+public:
+    int removeDuplicates(vector<int>& nums) {
+        nums.erase(unique(nums.begin(), nums.end()), nums.end());
+        return nums.size();
+    }
+};
+```
+
 ### **Go**
 
 ```go

solution/0000-0099/0026.Remove Duplicates from Sorted Array/Solution.cpp

@@ -1,10 +1,7 @@
 class Solution {
 public:
     int removeDuplicates(vector<int>& nums) {
-        int i = 0;
-        for (int& num : nums)
-            if (i < 1 || num != nums[i - 1]) 
-                nums[i++] = num;
-        return i;
+        nums.erase(unique(nums.begin(), nums.end()), nums.end());
+        return nums.size();
     }
-};
+};