69\. Sqrt(x)

Easy

Given a non-negative integer `x`, compute and return _the square root of_ `x`.

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

**Note:** You are not allowed to use any built-in exponent function or operator, such as `pow(x, 0.5)` or `x ** 0.5`.

**Example 1:**

**Input:** x = 4

**Output:** 2 

**Example 2:**

**Input:** x = 8

**Output:** 2

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

**Constraints:**

*   <code>0 <= x <= 2<sup>31</sup> - 1</code>
