Sync LeetCode submission - Single Element in a Sorted Array (cpp)

LeetCode/problems/single_element_in_a_sorted_array/solution.cpp

@@ -0,0 +1,28 @@
+class Solution {
+public:
+    int singleNonDuplicate(vector<int>& nums) 
+    {
+        int n=nums.size();
+        if(n==1 or nums[0]!=nums[1]) return nums[0];
+        if(nums[n-2]!=nums[n-1]) return nums[n-1];
+
+        int left=0, right=n-1;
+
+        int mid;
+
+        while(left<=right)
+        {
+            mid = (left+right)/2;
+            if(nums[mid]!=nums[mid-1] and nums[mid]!=nums[mid+1])
+                return nums[mid];
+
+            else if(mid%2==0 and nums[mid]==nums[mid+1] or (mid%2==1 and nums[mid]==nums[mid-1]))
+                left=mid+1;
+
+            else
+                right=mid-1;
+        }
+
+        return -1;        
+    }
+};