[Глава 5] Поиск в ширину

Chapter5_BreadthFirstSearch/Bfs.cs

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+using GrokAlgorithms.Chapter5_BreadthFirstSearch;
+
+static class Bfs
+{
+    public static TreeNode<T>? Search<T>(TreeNode<T> root, Func<T, bool> condition)
+    {
+        Queue<TreeNode<T>> queue = new();
+        queue.Enqueue(root);
+        HashSet<TreeNode<T>> visited = [];
+        while (queue.Count > 0)
+        {
+            var curr = queue.Dequeue();
+            if (visited.Contains(curr))
+                continue;
+            if (condition(curr.Value))
+                return curr;
+            foreach (var child in curr.Children)
+                queue.Enqueue(child);
+            visited.Add(curr);
+        }
+        return null;
+    }
+}

Chapter5_BreadthFirstSearch/Chapter5_BreadthFirstSearch.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

Chapter5_BreadthFirstSearch/Program.cs

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+using GrokAlgorithms.Chapter5_BreadthFirstSearch;
+
+int count = 0;
+
+// Команда для построения дерева
+TreeNode<int> BuildTreeCommand(int value, int depth, int branchingFactor)
+{
+    var node = new TreeNode<int>(value) { Comment = $"{count++}" };
+    if (depth == 0) return node;
+
+    for (int i = 1; i <= branchingFactor; i++)
+        node.Children.Add(BuildTreeCommand(value + i * 10, depth - 1, branchingFactor));
+    return node;
+}
+
+// Команда для печати дерева
+void PrintTreeCommand(TreeNode<int> node, string indent = "")
+{
+    Console.WriteLine($"{indent}{node.Value} [{node.Comment}] {(node.Selected ? " Selected" : "")}");
+    foreach (var child in node.Children)
+        PrintTreeCommand(child, indent + "  ");
+}
+
+var root = BuildTreeCommand(1, 3, 2);
+var found = Bfs.Search(root, (num) => num > 25);
+if (found != null)
+    found.Selected = true;
+PrintTreeCommand(root);

Chapter5_BreadthFirstSearch/TreeNode.cs

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+namespace GrokAlgorithms.Chapter5_BreadthFirstSearch;
+
+
+public class TreeNode<T>
+{
+    public T Value { get; init; }
+    public string Comment { get; init; }
+    public List<TreeNode<T>> Children { get; init; }
+    public bool Selected { get; set; }
+
+    public TreeNode(T value)
+    {
+        Value = value;
+        Comment = "";
+        Children = new List<TreeNode<T>>();
+        Selected = false;
+    }
+}