static void Main(string[] args) { //Stack Operations Stack stack = new Stack(); stack.Push(70); stack.Push(30); stack.Push(56); stack.Display(); stack.Peek(); stack.Pop(); stack.IsEmpty(); stack.Display(); //Queue Operations Queue linkedListQueue = new Queue(); linkedListQueue.Enqueue(56); linkedListQueue.Enqueue(30); linkedListQueue.Enqueue(70); linkedListQueue.Dequeue(); linkedListQueue.Display(); }
public static void Parentheses() { Console.WriteLine("Please enter string with brackets:"); string k = Console.ReadLine(); Stack stack = new Stack(k.Length); int a = 0, b = 0; //Traverse string. for (int i = 0; i < k.Length; i++) { string str = k[i].ToString(); //push left parenthesis to stack. if (str.Equals("(") || str.Equals("{") || str.Equals("[")) { stack.Push(k[i]); a++; } //pop left parenthesis which is correspond right parenthesis while (str.Equals(")")) { b++; if (!stack.IsEmpty() && stack.Peek().ToString().Equals("(")) { stack.Pop(); break; } else { Console.WriteLine("invalid Parentheses"); return; } } while (str.Equals("]")) { b++; if (!stack.IsEmpty() && stack.Peek().ToString().Equals("[")) { stack.Pop(); break; } else { Console.WriteLine("invalid Parentheses"); return; } } while (str.Equals("}")) { b++; if (!stack.IsEmpty() && stack.Peek().ToString().Equals("{")) { stack.Pop(); break; } else { Console.WriteLine("invalid Parentheses"); return; } } } if (stack.IsEmpty() && a - b == 0) { Console.WriteLine("Valid Parentheses"); } else if (a > b) { Console.WriteLine("invalid Parentheses"); } }