0 ms sol using java (bit manipulation & binary search)
Bit manipulation\n\nclass Solution {\n    public int singleNonDuplicate(int[] nums) {\n        int res = 0;\n        for(int i=0;i<nums.length;i++)\n        {\n
Bit manipulation\n```\nclass Solution {\n    public int singleNonDuplicate(int[] nums) {\n        int res = 0;\n        for(int i=0;i<nums.length;i++)\n        {\n            res = res^nums[i];\n        }\n        return res;\n    }\n}\n```\nbinary search\n```\nclass Solution {\n    public int singleNonDuplicate(int[] nums) {\n        int start = 0,end = nums.length-1;\n        while(start < end)\n        {\n            int mid = start + (end-start)/2;\n            if(mid % 2 == 1)\n                mid--;\n            \n            if(nums[mid] != nums[mid+1])\n                end = mid;\n            else start = mid+2;\n        }\n        return nums[start];\n    }\n}\n```\n\nPlease upvote if u find my code easy to understand
['Bit Manipulation', 'Binary Tree', 'Java']