Олимпиадный тренинг

Задача . 15


Задача

Темы:
public class Rational
{
private int numerator;
private int denominator;
/** default constructor */
Rational()
{ /* implementation not shown */ }
/** Constructs a Rational with numerator n and
* denominator 1. */
Rational(int n)
{ /* implementation not shown */ }
/** Constructs a Rational with specified numerator and
* denominator. */
Rational(int numer, int denom)
{ /* implementation not shown */ }
/** @return numerator */
int numerator()
{ /* implementation not shown */ }
/** @return denominator */
int denominator()
{ /* implementation not shown */ }
/** Returns (this + r). Leaves this unchanged.
* @return this rational number plus r
* @param r a rational number to be added to this Rational
*/
public Rational plus(Rational r)
{ /* implementation not shown */ }
//Similarly for times, minus, divide
...
/** Ensures denominator > 0. */
private void fixSigns()
{ /* implementation not shown */ }
/** Ensures lowest terms. */
private void reduce()
{ /* implementation not shown */ }
}


The constructors in the Rational class allow initialization of Rational objects in several different ways. Which of the following will cause an error?

(A) Rational r1 = new Rational();
(B) Rational r2 = r1;
(C) Rational r3 = new Rational(2,-3);
(D) Rational r4 = new Rational(3.5);
(E) Rational r5 = new Rational(10);

time 1000 ms
memory 32 Mb
Правила оформления программ и список ошибок при автоматической проверке задач

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