Determining the integer part of the square root of a number

The method takes an integer n and returns its square root, discarding the fractional part (without rounding up).

Examples:

• 9 → 3
• 4 → 2
• 5 → 2 (√5 ≈ 2.23, integer part — 2)

class Sqrt {
    public int calculateSqrt(int n) {
        // TODO
    }
}