[英]Printing method that returns void to a text file
問這個問題我感覺像個菜鳥,但是在我當前的驅動程序中,我已經使用迭代器成功地將樹的預排序打印到文本文件中。 我不知道如何打印我的遞歸方法,因為我不能將它們放入 println 語句中,因為它們是無效方法。 我知道我應該讓該方法將編寫器作為參數,但不知道該怎么做(驅動程序的最后幾個 println 語句)。 任何幫助表示贊賞!
司機:
package driver;
import java.io.*;
import java.util.*;
public class Driver {
private static Scanner file;
static PrintWriter outputFilePrinter;
static Scanner inputFileScanner;
public static void main(String[] args) throws FileNotFoundException {
Scanner inFile; //Declaring scanner obj
PrintWriter printWriter = new PrintWriter("output.txt"); //Text file where results are printed to
inFile = new Scanner(new File("input.txt")); //Text file where student names and associated number are read from
BinarySearchTreeInterface<String> aTree = new BinarySearchTree<>() {}; //Giving access to BinarySearchTree methods
while (inFile.hasNext()) { //Scans input file
String name = inFile.nextLine(); //Assigns contents to string obj
aTree.add(name); //Add string to a tree
} //End while
Iterator<String> traverse = aTree.getPreorderIterator(); //Using iterator to print tree in an "postorder" fashion
while (traverse.hasNext())
printWriter.println(traverse.next()); //Prints tree
System.out.println("Postorder Recrusive: ");
aTree.postorderTraverse();
System.out.println("");
System.out.println("Inorder Recursive: ");
aTree.inorderTraverse();
printWriter.close(); //Closes file
} //End Main
} //End Driver
我試圖打印的遞歸方法:
public void inorderTraverse() {
inorderTraverse(root);
}
public void inorderTraverse(BinaryNode<T> node) {
if (node != null) {
inorderTraverse(node.getLeftChild());
System.out.println(node.getData());
inorderTraverse(node.getRightChild());
}
}
public void postorderTraverse() {
postorderTraverse(root);
}
public void postorderTraverse(BinaryNode<T> node) {
if (node != null) {
postorderTraverse(node.getLeftChild());
postorderTraverse(node.getRightChild());
System.out.println(node.getData());
}
}
您可以將遍歷代碼更改為
public void inorderTraverse(PrintWriter printWriter) {
inorderTraverse(root, printWriter);
}
public void inorderTraverse(BinaryNode<T> node, PrintWriter printWriter) {
if (node != null) {
inorderTraverse(node.getLeftChild(), printWriter);
printWriter.println(node.getData());
inorderTraverse(node.getRightChild(), printWriter);
}
}
public void postorderTraverse(PrintWriter printWriter) {
postorderTraverse(root, printWriter);
}
public void postorderTraverse(BinaryNode<T> node, PrintWriter printWriter) {
if (node != null) {
postorderTraverse(node.getLeftChild(), printWriter);
postorderTraverse(node.getRightChild(), printWriter);
printWriter.println(node.getData());
}
}
甚至
public void inorderTraverse(Consumer<T> consumer) {
inorderTraverse(root, consumer);
}
public void inorderTraverse(BinaryNode<T> node, Consumer<T> consumer) {
if (node != null) {
inorderTraverse(node.getLeftChild(), consumer);
consumer.accept(node.getData());
inorderTraverse(node.getRightChild(), consumer);
}
}
public void postorderTraverse(Consumer<T> consumer) {
postorderTraverse(root, consumer);
}
public void postorderTraverse(BinaryNode<T> node, Consumer<T> consumer) {
if (node != null) {
postorderTraverse(node.getLeftChild(), consumer);
postorderTraverse(node.getRightChild(), consumer);
consumer.accept(node.getData());
}
}
並像這樣調用第二個變體:
aTree.postorderTraverse(printWriter::println);
aTree.postorderTraverse(System.out::println);
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.