Brackets

        /// <summary>
        /// Solution
        /// 100/100
        /// </summary>
        /// <param name="S"></param>
        /// <returns></returns>
        public static int solution(string S)
        {
            Stack<char> stack = new Stack<char>();
            foreach (char ch in S)
            {
                if (stack.Count > 0)
                {
                    if (stack.Peek() == '(' && ch == ')' || stack.Peek() == '[' && ch == ']' || stack.Peek() == '{' && ch == '}')
                        stack.Pop();
                    else
                        stack.Push(ch);
                }
                else
                {
                    stack.Push(ch);
                }
            }
            if (stack.Count > 0)
                return 0;
            else
                return 1;
        }