SSE

You are given a number 'N' in the form of a string 'S', which is a palindrome. You need to find the greatest number strictly less than 'N' which is also a palindrome.

Note:

1. A palindrome is a word, number, phrase, or another sequence of characters that reads the same backward as forward, such as madam, racecar, 1234321, etc.
2. The numerical value of the given string S will be greater than 0.
3. A single-digit number is also considered a palindrome.
4. The answer number should not contain any leading zeros, except for the case when the answer is 0.
5. Note that the length of the string is nothing but the number of digits in N.

Given an integer ‘N’ representing the number of pairs of parentheses, Find all the possible combinations of balanced parentheses with the given number of pairs of parentheses.

Note :

Conditions for valid parentheses:
1. All open brackets must be closed by the closing brackets.

2. Open brackets must be closed in the correct order.

For Example :

()()()() is a valid parentheses.
)()()( is not a valid parentheses.

You are given an array Arr consisting of n integers, you need to find all the distinct triplets present in the array which adds up to zero.

An array is said to have a triplet {arr[i], arr[j], arr[k]} with 0 sum if there exists three indices i, j and k such that i!=j, j!=k and i!=k and arr[i] + arr[j] + arr[k] = 0.

Note :

1. You can return the list of values in any order. For example, if a valid triplet is {1, 2, -3}, then (2, -3, 1), (-3, 2, 1) etc is also valid triplet. Also, the ordering of different triplets can be random i.e if there are more than one valid triplets, you can return them in any order.
2. The elements in the array need not be distinct.
3. If no such triplet is present in the array, then return an empty list, and the output printed for such a test case will be "-1".

What are nested interfaces?