balanced.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace BalancedParens
{
	class Program
	{
		private static Dictionary<char, char> openingToClose = new Dictionary<char, char>() {
			{ '{', '}' },
			{ '[', ']' },
			{ '(', ')' }
		};

		static bool Balanced(string body)
		{
			var expectedCloses = new Stack<char>();
			foreach(var c in body)
			{
				if (openingToClose.ContainsKey(c))
				{
					expectedCloses.Push(openingToClose[c]);
				}
				else
				{
					var expectedClose = expectedCloses.Pop();
					if (!c.Equals(expectedClose))
					{
						return false;
					}
				}
			}
			return expectedCloses.Count == 0;
		}

		static void Main(string[] args)
		{
			var testCases = new Dictionary<string, bool> {
				{ "{}[]()", true},
				{ "{}[()]", true},
				{ "[{}()]", true },
				{ "[(])", false },
				{ "([{])}", false },
				{ "([{", false }
			};

			foreach (var testCase in testCases)
			{
				var result = Balanced(testCase.Key);
				if (result != testCase.Value)
				{
					Console.WriteLine(testCase.Key + " Should Be: " + testCase.Value.ToString());
				}
				else
				{
					Console.WriteLine(testCase.Key + "Correct");
                }
			}
			Console.ReadKey();
		}
	}
}