SDE - 1

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.

You have been given two strings 'STR1' and 'STR2'. You have to check whether the two strings are anagram to each other or not.

Note:

Two strings are said to be anagram if they contain the same characters, irrespective of the order of the characters.

Example :

If 'STR1' = “listen” and 'STR2' = “silent” then the output will be 1.

Both the strings contain the same set of characters.

You have been given a Binary Tree of integers. You are supposed to return the level order traversal of the given tree.

For example:

For the given binary tree

The level order traversal will be {1,2,3,4,5,6,7}.

You are given an arbitrary binary tree consisting of N nodes numbered from 1 to N, an integer 'K', and a node 'TARGET_NODE_VAL' from the tree. You need to find the Kth ancestor of the node 'TARGET_NODE_VAL'. If there is no such ancestor, then print -1.

The Kth ancestor of a node in a binary tree is the Kth node in the path going up from the given node to the root of the tree. Refer to sample test cases for further explanation.

Note:

1. The given node 'TARGET_NODE_VAL' is always present in the tree.
2. The value of each node in the tree is unique.
3. Notice that the Kth ancestor node if present will always be unique.

You have been given an array/list 'SEQUENCE' denoting the sequence of 'N' integers. Your task is to find the equilibrium indices of the sequence in 'SEQUENCE'.

The equilibrium index of a sequence of integers is defined as the index such that the sum of all the elements at lower indices is equal to the sum of elements at higher indices.

Note:

1. 'SEQUENCE' may contain more than one equilibrium indices.

2. If there are no equilibrium indices, return an empty sequence.

3. Consider the sum of elements lower than the first index and higher than the last index to be 0 (zero).

You have been given a Binary Search Tree of integers. You are supposed to convert it to a greater sum tree such that the value of every node in the given BST is replaced with the sum of the values of all the nodes which are greater than the value of the current node in the tree.

A Binary Search Tree is a tree, whose internal nodes each store a value greater than all the values in the node's left subtree and less than those in its right subtree.

Note :

You need to modify the given tree only. You are not allowed to create a new tree.

For example:

For the given binary search tree

11 will be replaced by {15 + 29 + 35 + 40}, i.e. 119.
2 will be replaced by {7 + 11 + 15 + 29 + 35 + 40}, i.e. 137.
29 will be replaced by {35 + 40}, i.e. 75.
1 will be replaced by {2 + 7 + 11 + 15 + 29 + 35 + 40}, i.e. 139.
7 will be replaced by {11 + 15 + 29 + 35 + 40}, i.e. 130.
15 will be replaced by {15 + 29 + 35 + 40}, i.e. 104.
40 will be replaced by 0 {as there is no node with a value greater than 40}.
35 will be replaced by {40}, i.e. 40.