Added sorted linked list

data_structures/linked_list/sorted_linked_list.dart

@@ -0,0 +1,183 @@
+import 'package:test/test.dart';
+
+class SortedLinkedList {
+  Node? _head;
+  Node? _tail;
+
+  SortedLinkedList() {
+    _head = null;
+    _tail = null;
+  }
+
+  /// Inserts a new element into the sorted linked list.
+  void insert(int value) {
+    Node newNode = Node(value);
+    if (_head == null) {
+      _head = newNode;
+      _tail = newNode;
+    } else if (value < _head!.value) {
+      newNode.next = _head;
+      _head = newNode;
+    } else if (value > _tail!.value) {
+      _tail!.next = newNode;
+      _tail = newNode;
+    } else {
+      Node? temp = _head;
+      while (temp!.next != null && temp.next!.value < value) {
+        temp = temp.next;
+      }
+      newNode.next = temp.next;
+      temp.next = newNode;
+      if (newNode.next == null) {
+        _tail = newNode;
+      }
+    }
+  }
+
+  /// Displays the elements of the sorted linked list.
+  void display() {
+    print(toString());
+  }
+
+  /// Deletes the first occurrence of the specified element in the sorted linked list.
+  bool delete(int value) {
+    if (_head == null) {
+      return false;
+    } else if (_head!.value == value) {
+      if (_head!.next == null) {
+        _head = null;
+        _tail = null;
+      } else {
+        _head = _head!.next;
+      }
+      return true;
+    } else {
+      Node? temp = _head;
+      while (temp!.next != null) {
+        if (temp.next!.value == value) {
+          if (temp.next == _tail) {
+            _tail = temp;
+          }
+          temp.next = temp.next!.next;
+          return true;
+        }
+        temp = temp.next;
+      }
+      return false;
+    }
+  }
+
+  /// Searches for the specified element in the sorted linked list.
+  bool search(int value) {
+    Node? temp = _head;
+    while (temp != null) {
+      if (temp.value == value) {
+        return true;
+      }
+      temp = temp.next;
+    }
+    return false;
+  }
+
+  /// Checks if the sorted linked list is empty.
+  bool isEmpty() {
+    return _head == null;
+  }
+
+  /// Returns a string representation of the sorted linked list.
+  @override
+  String toString() {
+    if (_head != null) {
+      List<String> elements = [];
+      Node? temp = _head;
+      while (temp != null) {
+        elements.add(temp.value.toString());
+        temp = temp.next;
+      }
+      return '[${elements.join(', ')}]';
+    } else {
+      return '[]';
+    }
+  }
+}
+
+class Node {
+  final int value;
+  Node? next;
+
+  Node(this.value) {
+    next = null;
+  }
+}
+
+void main() {
+  group('SortedLinkedList', () {
+    test('insert adds elements in sorted order', () {
+      final list = SortedLinkedList();
+      list.insert(3);
+      list.insert(1);
+      list.insert(2);
+
+      expect(list.toString(), equals('[1, 2, 3]'));
+    });
+
+    test('delete removes an element from the list', () {
+      final list = SortedLinkedList();
+      list.insert(1);
+      list.insert(2);
+      list.insert(3);
+
+      final result = list.delete(2);
+
+      expect(result, equals(true));
+      expect(list.toString(), equals('[1, 3]'));
+    });
+
+    test('delete returns false for non-existent element', () {
+      final list = SortedLinkedList();
+      list.insert(1);
+      list.insert(2);
+      list.insert(3);
+
+      final result = list.delete(4);
+
+      expect(result, equals(false));
+      expect(list.toString(), equals('[1, 2, 3]'));
+    });
+
+    test('isEmpty returns true for an empty list', () {
+      final list = SortedLinkedList();
+
+      expect(list.isEmpty(), equals(true));
+    });
+
+    test('isEmpty returns false when the list has elements', () {
+      final list = SortedLinkedList();
+      list.insert(1);
+
+      expect(list.isEmpty(), equals(false));
+    });
+
+    test('search finds an element in the list', () {
+      final list = SortedLinkedList();
+      list.insert(1);
+      list.insert(2);
+      list.insert(3);
+
+      final result = list.search(2);
+
+      expect(result, equals(true));
+    });
+
+    test('search returns false for an element not in the list', () {
+      final list = SortedLinkedList();
+      list.insert(1);
+      list.insert(2);
+      list.insert(3);
+
+      final result = list.search(4);
+
+      expect(result, equals(false));
+    });
+  });
+}