69. Sqrt(x)

[copy title]:

Implement int sqrt(int x).

Compute and return the square root of x, where x is guaranteed to be a non-negative integer.

Since the return type is an integer, the decimal digits are truncated and only the integer part of the result is returned.

Example 1:

Input: 4
Output: 2

Example 2:

Input: 8
Output: 2
Explanation: The square root of 8 is 2.82842..., and since
             the decimal part is truncated, 2 is returned.

 [brute force solution]:

Time analysis:

Space Analysis:

 [Optimized]:

Time analysis:

Space Analysis:

[Wonderful output conditions]:

[Wonderful corner case]:

[Thinking question]:

[One sentence idea]:

[Input amount]: Empty: Normal situation: Extra large: Extra small: Special situations handled in the program: Abnormal situations (Illegal and unreasonable input):

[Paint]:

[One brush]:

[Second brush]:

[Three brushes]:

[Four brushes]:

[Five brushes]:

  [Results of five-minute naked eye debug]:

[Summarize]:

[Complexity]: Time complexity: O( ) Space complexity: O( )

[English data structures or algorithms, why not use other data structures or algorithms]:

[Key templating code]:

[Other solutions]:

［Follow Up］：

[The topics given by LC change and change]:

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