91 lines
2.4 KiB
Java
91 lines
2.4 KiB
Java
package Searches;
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import java.util.ArrayList;
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import java.util.List;
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import java.util.Objects;
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import java.util.Optional;
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/**
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* @author: caos321
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* @date: 31 October 2021 (Sunday)
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*/
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public class DepthFirstSearch {
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static class Node {
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private final String name;
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private final List<Node> subNodes;
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public Node(final String name) {
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this.name = name;
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this.subNodes = new ArrayList<>();
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}
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public Node(final String name, final List<Node> subNodes) {
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this.name = name;
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this.subNodes = subNodes;
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}
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public String getName() {
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return name;
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}
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public List<Node> getSubNodes() {
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return subNodes;
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}
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}
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public static Optional<Node> search(final Node node, final String name) {
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if (node.getName().equals(name)) {
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return Optional.of(node);
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}
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return node.getSubNodes()
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.stream()
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.map(value -> search(value, name))
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.flatMap(Optional::stream)
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.findAny();
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}
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public static void assertThat(final Object actual, final Object expected) {
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if (!Objects.equals(actual, expected)) {
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throw new AssertionError(String.format("expected=%s but was actual=%s", expected, actual));
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}
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}
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public static void main(final String[] args) {
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final Node rootNode = new Node("A", List.of(
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new Node("B", List.of(new Node("D"), new Node("F", List.of(
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new Node("H"), new Node("I")
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)))),
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new Node("C", List.of(new Node("G"))),
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new Node("E")
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));
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{
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final String expected = "I";
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final Node result = search(rootNode, expected)
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.orElseThrow(() -> new AssertionError("Node not found!"));
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assertThat(result.getName(), expected);
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}
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{
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final String expected = "G";
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final Node result = search(rootNode, expected)
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.orElseThrow(() -> new AssertionError("Node not found!"));
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assertThat(result.getName(), expected);
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}
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{
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final String expected = "E";
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final Node result = search(rootNode, expected)
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.orElseThrow(() -> new AssertionError("Node not found!"));
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assertThat(result.getName(), expected);
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}
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}
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}
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