From a16c9e3c901ecbae22ad9fced38b8bd90c5ddef5 Mon Sep 17 00:00:00 2001
From: xzero <andrejmezler@yahoo.de>
Date: Sun, 31 Oct 2021 20:30:43 +0100
Subject: [PATCH 1/2] Add DepthFirstSearch with Java Streams

Add simple DepthFirstSearch with Java Streams
---
 Searches/DepthFirstSearch.java | 86 ++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 Searches/DepthFirstSearch.java

diff --git a/Searches/DepthFirstSearch.java b/Searches/DepthFirstSearch.java
new file mode 100644
index 000000000000..f90dc495bcf8
--- /dev/null
+++ b/Searches/DepthFirstSearch.java
@@ -0,0 +1,86 @@
+package Searches;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+
+public class DepthFirstSearch {
+    static class Node {
+        private final String name;
+        private final List<Node> subNodes;
+
+        public Node(final String name) {
+            this.name = name;
+            this.subNodes = new ArrayList<>();
+        }
+
+        public Node(final String name, final List<Node> subNodes) {
+            this.name = name;
+            this.subNodes = subNodes;
+        }
+
+        public String getName() {
+            return name;
+        }
+
+        public List<Node> getSubNodes() {
+            return subNodes;
+        }
+    }
+
+    public static Optional<Node> search(final Node node, final String name) {
+        if (node.getName().equals(name)) {
+            return Optional.of(node);
+        }
+
+        return node.getSubNodes()
+                .stream()
+                .map(value -> search(value, name))
+                .flatMap(Optional::stream)
+                .findAny();
+    }
+
+    public static void assertThat(final Object actual, final Object expected) {
+        if (!Objects.equals(actual, expected)) {
+            throw new AssertionError(String.format("expected=%s but was actual=%s", expected, actual));
+        }
+    }
+
+    public static void main(final String[] args) {
+        final Node rootNode = new Node("A", List.of(
+                new Node("B", List.of(new Node("D"), new Node("F", List.of(
+                        new Node("H"), new Node("I")
+                )))),
+                new Node("C", List.of(new Node("G"))),
+                new Node("E")
+        ));
+
+        {
+            final String expected = "I";
+
+            final Node result = search(rootNode, expected)
+                    .orElseThrow(() -> new AssertionError("Node not found!"));
+
+            assertThat(result.getName(), expected);
+        }
+
+        {
+            final String expected = "G";
+
+            final Node result = search(rootNode, expected)
+                    .orElseThrow(() -> new AssertionError("Node not found!"));
+
+            assertThat(result.getName(), expected);
+        }
+
+        {
+            final String expected = "E";
+
+            final Node result = search(rootNode, expected)
+                    .orElseThrow(() -> new AssertionError("Node not found!"));
+
+            assertThat(result.getName(), expected);
+        }
+    }
+}

From e0e233f451c4aae1d866246f5e50d30e8fdc73d6 Mon Sep 17 00:00:00 2001
From: xzero <andrejmezler@yahoo.de>
Date: Sun, 31 Oct 2021 20:33:45 +0100
Subject: [PATCH 2/2] Add author name and date

---
 Searches/DepthFirstSearch.java | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Searches/DepthFirstSearch.java b/Searches/DepthFirstSearch.java
index f90dc495bcf8..bca2685cf625 100644
--- a/Searches/DepthFirstSearch.java
+++ b/Searches/DepthFirstSearch.java
@@ -5,6 +5,10 @@
 import java.util.Objects;
 import java.util.Optional;
 
+/**
+ * @author:  caos321
+ * @date:    31 October 2021 (Sunday)
+ */
 public class DepthFirstSearch {
     static class Node {
         private final String name;