8241. Function – 3

Implement the function f(x, y) = x² + sin(x * y) – y².

Input. Each line contains two real numbers x and y.

Output. For each test case, print on a separate line the value of the function f(x, y) with four decimal places.

Sample input	Sample output
2.234 2.12 10 23 56.1 0.012 23.26 5.1	-0.5034 -429.6161 3147.8333 514.3327

SOLUTION

functions

Algorithm analysis

Implement the funtion f(x, y). Read the input data until the end of the file.

Algorithm implementation

Implement the function f.

double f(double x, double y)

{

return x * x + sin(x * y) - y * y;

}

The main part of the program. Read the input data until the end of the file.

while (scanf("%lf %lf", &x, &y) == 2)

printf("%.4lf\n", f(x, y));

Java implementation

import java.util.*;

public class Main

{

static double f(double x, double y)

{

return x * x + Math.sin(x * y) - y * y;

}

public static void main(String[] args)

{

Scanner con = new Scanner(System.in);

while(con.hasNext())

{

double x = con.nextDouble();

double y = con.nextDouble();

System.out.printf("%.4f\n",f(x,y));

}

con.close();

}

}

Python implementation

import sys

import math

Implement the function f.

def f(x,y):

return x * x + math.sin(x * y) - y * y

The main part of the program. Read the input data until the end of the file.

for x in sys.stdin:

x, y = map(float, x.split())

print(f(x,y))