Value of variable 1#8825

Value of variable 1 (Editorial)

To solve the problem, compute the value of the given expression.

Algorithm implementation

Read the value of the variable $x$ .

scanf("%lf", &x);

Compute the value of the variable $y$ .

y = x * x * x - 5 * x * x / 7 + 9 * x - 3 / x + 1;

Print the result rounded to three decimal places.

printf("%.3lf\n", y);

Java implementation

import java.util.*;

class Main 
{
  public static void main(String[] args) 
  {
    Scanner con = new Scanner(System.in);
    double x = con.nextDouble();
    double y = x * x * x - 5 * x * x / 7 + 9 * x - 3 / x + 1;
    System.out.printf("%.3f",y);
    con.close();
  }
}

Java

Java implementation — class MyDouble

import java.util.*;

class MyDouble
{
  private double a;
  
  MyDouble(double a)
  {
    this.a = a;
  }

  MyDouble Add(MyDouble b)
  {
    return new MyDouble(a + b.a); 
  }

  MyDouble Add(double b)
  {
    return new MyDouble(a + b); 
  }

  MyDouble Sub(MyDouble b)
  {
    return new MyDouble(a - b.a); 
  }
  
  MyDouble Mult(MyDouble b)
  {
    return new MyDouble(a * b.a); 
  }

  MyDouble Divide(MyDouble b)
  {
    return new MyDouble(a / b.a); 
  }

  MyDouble Divide(double b)
  {
    return new MyDouble(a / b); 
  }
  
  public String toString()
  {
    return String.format("%.3f", a);
  }
}

public class Main
{
  public static void main(String[] args) 
  {
    Scanner con = new Scanner(System.in);
    MyDouble x = new MyDouble(con.nextDouble());
    MyDouble a = x.Mult(x).Mult(x); // x^3
    MyDouble b = new MyDouble(5).Mult(x).Mult(x).Divide(7); // 5 * x * x / 7
    MyDouble c = new MyDouble(9).Mult(x); // 9 * x
    MyDouble d = new MyDouble(3).Divide(x); // 3 / x

    MyDouble res = a.Sub(b).Add(c).Sub(d).Add(1);
    System.out.println(res);
    con.close();
  }
}

Java

Python implementation

Read the value of the variable $x$ .

x = float(input())

Compute the value of the variable $y$ .

y = x * x * x - 5 * x * x / 7 + 9 * x - 3 / x + 1

Print the result.

print(y)