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class Solution {
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  public int singleNonDuplicate(int[] nums) {
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    if (nums.length == 1) return nums[0];
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    int l = 0;
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    int h = nums.length - 1;
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    while (l < h) {
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      int mid = l + (h - l) / 2; // divide the array
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      if (nums[mid] == nums[mid + 1]) mid = mid - 1; // two same elements should be in same half
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      if ((mid - l + 1) % 2 != 0)
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        h = mid; // checking the length of left half. If its is odd then update ur right pointer to
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      // mid
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      else l = mid + 1; // else your right half will be odd then update your left pointer to mid+1
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    }
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    return nums[l]; // left pointer will have the answer at last
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  }
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}