Balance.java

    public static boolean balance(String str) {
		HashMap<String, String> delimMap = new HashMap<String, String>();
		delimMap.put("{", "}");
		delimMap.put("(", ")");

		Stack<Character> delimStack = new Stack<Character>();
		for (int i = 0; i < str.length(); i++) {
			if (delimMap.containsKey(String.valueOf(str.charAt(i)))) {
				delimStack.push(str.charAt(i));
			} else {
				if (!delimStack.empty()) {
					String lastOpen = delimStack.pop().toString();
					if (!delimMap.get(lastOpen).equals(String.valueOf(str.charAt(i)))) {
						return false;
					}
				} else {
					return false;
				}
			}
		}
		if (!delimStack.empty()) {
			return false;
		}
		return true;
	}