Blue Bridge Cup: Introductory training round area "Java algorithm implementation"

Title Description

The radius of the given circle R, to find the area of the circle.

Input format

The input contains an integer r that represents the radius of the circle

Output format

The output line, containing a real number, rounded to retain 7 digits after the decimal point, indicating the area of the circle.

Description: In the subject, the input is an integer, but the output is a real number.

For the real output of the problem, please be sure to see the real output of the requirements, such as the need to retain the decimal point 7, your program must be strictly output 7 decimal places, output too much or too little number of decimal places are not, will be considered wrong.

The problem with the real output if not specifically stated, rounding is done by rounding.

Sample input

4

Sample output

50.2654825

Data size and conventions

1 <= R <= 10000.

Import Java.text.decimalformat;import Java.util.scanner;public class Main {public static void main (string[] args) { Scanner cin = new Scanner (system.in);d ouble pi=3.14159265358979323;double n=cin.nextint ();d ouble s=n*n*pi;d Ecimalformat df = new DecimalFormat ("###.0000000"); System.out.println (Df.format (s));}}

Blue Bridge Cup: Introductory training round area "Java algorithm implementation"