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I am trying to write a generic Heap Sort algorithm. I get the following error. What could be the reason?
The type
Tcannot be used as type parameterTin the generic type or methodHeap.MainClass.MaxHeapify<T>(T[], int, int). There is no boxing or type parameter conversion fromTtoSystem.IComparable<T>(CS0314) (HeapSort)
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Function types can create generics in the same way as normal functions, by adding the type parameter list <T> before the function type parameter list. You can use generics in the same places you'd add any other type in a function type (parameter or return types). Which then gets used as its own type.
For static generic methods, the type parameter section must appear before the method's return type. The complete syntax for invoking this method would be: Pair<Integer, String> p1 = new Pair<>(1, "apple"); Pair<Integer, String> p2 = new Pair<>(2, "pear"); boolean same = Util. <Integer, String>compare(p1, p2);
Yes, you can define a generic method in a non-generic class in Java.
Generic is a class which allows the user to define classes and methods with the placeholder. Generics were added to version 2.0 of the C# language. The basic idea behind using Generic is to allow type (Integer, String, … etc and user-defined types) to be a parameter to methods, classes, and interfaces.
You need to specify the same generic constraint that T must implement IComparable<T> on the HeapSort function as well:
private static void HeapSort<T>(T[] items) where T : IComparable<T>
You specified this constraint on the MaxHeapify method and in order to call it, T must satisfy this condition.
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The MaxHeapify<T>() method has a generic constraint of where T : IComparable but your HeapSort<T>() method doesn't have it, and so the compiler is not able to resolve the call to MaxHeapify from HeapSort method.
You should add a generic constraint of where : IComparable to your HeapSort<T>() method also.
private static void HeapSort<T>(T[] items) where T : IComparable<T>
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