48 lines
616 B
Markdown
48 lines
616 B
Markdown
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---
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layout: page
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title: Missing Number
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---
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#### sort
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#### hashset
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#### gauss equation
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{% highlight python %}
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def missingNumber(self, nums: List[int]) -> int:
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n=len(nums)
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expected = (n*(n+1))//2
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actual = sum(nums)
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return expected-actual
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{% endhighlight %}
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#### xor
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{% highlight python %}
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nums = [3,0,1]
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n = len(nums)
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# xor index with value
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xor = 0
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for i, num in enumerate(nums):
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xor ^= i^num
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# xor with length gives you missing num
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missing = xor^n
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print(missing)
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{% endhighlight %}
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