Java By Examples

JavaByExamples

1. How to find out second hightest value from a Map<String, Integer>
	Map<String, Integer> books = new HashMap<>();
	books.put("one", 1);
	books.put("two", 22);
	books.put("three", 333);
	books.put("four", 4444);
	books.put("five", 55555);
	books.put("six", 666666);
	Stream<Integer> list = books.entrySet().stream().filter(e -> e.getValue().toString().length() > 3)
				.map(Map.Entry::getValue);
	List<Integer> valuesList = list.collect(Collectors.toList());
	valuesList.sort(Comparator.naturalOrder());
	Object o = valuesList.toArray()[1];
	System.out.println(o);

2. Find whether given string is valid or not. 
		String str = "{{{{}}}}";
		int openB = 0;
		char[] charArray = str.toCharArray();
		for (char chr : charArray) {
			if (chr == '{') {
				openB += 1;
			} else {
				openB -= 1;
			}
		}
		if (openB == 0) {
			System.out.println("valid");
		} else {
			System.out.println("in-valid");
		}
3. Find 2nd Hightest number from a given int array
	int arr[] = {12, 35, 1, 10, 34, 1};
		int i, first, second;
		first = second = Integer.MIN_VALUE;
        for (i = 0; i < arr.length; i++) {
            /* If current element is smaller than 
            first then update both first and second */
            if (arr[i] > first) {
                second = first;
                first = arr[i];
            } else if (arr[i] > second && arr[i] != first)  {
		second = arr[i];
	    }
        }
        System.out.println(second);