不兼容类型：int不能转换为T

Question

下面是我的代码：

import java.util.Scanner;
import java.util.Queue;
import java.util.LinkedList;

public class BinarySearchTree<T extends java.lang.Comparable<? super T>>
{

    private static class BinaryNode<T>
    {
        private T element; // The data in the node
        private BinaryNode<T> left; // Left child
        private BinaryNode<T> right; // Right child

        // Constructors
        BinaryNode( T theElement )
        {
            this( theElement, null, null );
        }

        BinaryNode( T theElement, BinaryNode<T> lt, BinaryNode<T> rt )
        {
            element = theElement;
            left = lt;
            right = rt;
        }
    }

    private BinaryNode<T> root; //root node of the tree

    // Constructor
    public BinarySearchTree( )
    {
        root = null;
    }

    /***************************************************
    * FUNCTION isEmpty: isEmpty *
    * checks if the tree is empty *
    * INPUT PARAMETERS: none *
    * none *
    * OUTPUT: boolean *
    * true if the tree is empty, false otherwise *
    ****************************************************/
    public boolean isEmpty( )
    {
        return root == null;
    }

    private BinaryNode<T> findMin( BinaryNode<T> t )
    {
        if( t == null )
            return null;
        else if( t.left == null )
            return t;
        return findMin( t.left );
    }

    /***************************************************
    * FUNCTION insert: insert *
    * inserts an item into the tree *
    * INPUT PARAMETERS: x *
    * x - the item to be added to the BST *
    * OUTPUT: none *
    * none *
    ****************************************************/
    public void insert( T x )
    {
        root = insert( x, root );
    }

    /***************************************************
    * FUNCTION insert: insert helper method *
    * inserts an item into the tree *
    * INPUT PARAMETERS: x, t *
    * x - the item to be added to the BST, subtree to be inserted in *
    * OUTPUT: BinaryNode<T> *
    * node to be set *
    ****************************************************/
    public  BinaryNode<T> insert( T x, BinaryNode<T> t )
    {
        if( t == null )
            return new BinaryNode<T>( x, null, null );

        int compareResult = x.compareTo( t.element );

        if( compareResult < 0 )
        {
            t.left = insert( x, t.left );
        }
        else if( compareResult > 0 )
        {
            t.right = insert( x, t.right );
        }
        else
        ; // Duplicate; do nothing
        return t;
    }

    /***************************************************
    * FUNCTION insertList: Option 1 *
    * parses a string and insert the values contained in it *
    * INPUT PARAMETERS: csv *
    * csv - comma seperated list of integers *
    * OUTPUT: none *
    * none *
    ****************************************************/
    public void insertList(String csv)
    {
        String[] inputValues = csv.split(",") ; // Numbers are seperated by comma as instructed
        for (String x : inputValues)
        {
            int y = Integer.parseInt(x);
            insert(y);
        }
    }
}

Answer 1

您有一个泛型参数，因此在读取CSV时创建一个新树在逻辑上是正确的。

这也意味着InsertList（...）应该变成静态的，现在可以像BinarySearchTree tree=BinarySearchTree.InsertList（...） 那样调用

代码如下：

    public static void insertList(String csv)
    {
        String[] inputValues = csv.split(",") ; // Numbers are seperated by comma as instructed
        BinarySearchTree<Integer> tree = new BinarySearchTree<>();
        for (String x : inputValues)
        {
            int y = Integer.parseInt(x);
            tree.insert(y);
        }
    }