SDE - 1

You are given a string 'STR'. The string contains [a-z] [A-Z] [0-9] [special characters]. You have to find the reverse of the string.

For example:

 If the given string is: STR = "abcde". You have to print the string "edcba".

follow up:

Try to solve the problem in O(1) space complexity. 

You are given an array consisting of 'N' positive integers where each integer is either 0 or 1 or 2. Your task is to sort the given array in non-decreasing order.

Note :

1. The array consists of only 3 distinct integers 0, 1, 2.
2. The array is non-empty.

You are given the root node of a binary tree with N nodes, whose nodes have integer values. Your task is to find the maximum depth of the given Binary tree.

Depth of a binary tree is the same as its height. In simpler terms, you have to find the total number of nodes encountered while moving from the root node to the farthest leaf node, along the longest path of the binary tree.

Example:-

If we are given the above binary tree as input then moving from root node(5) to the farthest leaf node(50), the path formed will be [ 5->10->25->35->40->45->50 ]. The total number of nodes encountered is 7, therefore the maximum depth of the binary tree is 7.

Reverse a given stack of 'N' integers using recursion. You are required to make changes in the input parameter itself.

Note: You are not allowed to use any extra space other than the internal stack space used due to recursion.

Example:

Input: [1,2,3,4,5] 
Output: [5,4,3,2,1]

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