SDE - 1

You are given an integer ‘N’. Your task is to find all palindromic numbers from 1 to ‘N’.

Palindromic integers are those integers that read the same backward or forwards.

Note:

Order of numbers should be in the non-decreasing matter.

For example:

You are given ‘N’ as 12, so the output should be [1, 2, 3, 4, 5, 6, 7, 8, 9, 11], as all single-digit numbers are palindromic, and 11 is also a palindromic number.

You are given a square matrix of non-negative integers 'MATRIX'. Your task is to rotate that array by 90 degrees in an anti-clockwise direction using constant extra space.

For example:

For given 2D array :

    [    [ 1,  2,  3 ],
         [ 4,  5,  6 ],
         [ 7,  8,  9 ]  ]

After 90 degree rotation in anti clockwise direction, it will become:

    [   [ 3,  6,  9 ],
        [ 2,  5,  8 ],
        [ 1,  4,  7 ]   ]

You are given a string 'str' of length 'N'.

Your task is to reverse the original string word by word.

There can be multiple spaces between two words and there can be leading or trailing spaces but in the output reversed string you need to put a single space between two words, and your reversed string should not contain leading or trailing spaces.

Example :

If the given input string is "Welcome to Coding Ninjas", then you should return "Ninjas Coding to Welcome" as the reversed string has only a single space between two words and there is no leading or trailing space.

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 a string 'S' containing only digits. Your task is to find all possible IP addresses that can be obtained from string 'S' in lexicographical order.

Note:

A valid IP address consists of exactly four integers, each integer is between 0 and 255 separated by single dots, and cannot have leading zeros except in the case of zero itself.

For example:

The following are valid IP addresses:
0.1.24.255
18.5.244.1

Following are invalid IP addresses:
0.01.24.255  (as  01  contains one leading zero).
18.312.244.1 (as 312 not lies between 0 and 255).

Aahad and Harshit always have fun by solving problems. Harshit took a sorted array consisting of distinct integers and rotated it clockwise by an unknown amount. For example, he took a sorted array = [1, 2, 3, 4, 5] and if he rotates it by 2, then the array becomes: [4, 5, 1, 2, 3].

After rotating a sorted array, Aahad needs to answer Q queries asked by Harshit, each of them is described by one integer Q[i]. which Harshit wanted him to search in the array. For each query, if he found it, he had to shout the index of the number, otherwise, he had to shout -1.

For each query, you have to complete the given method where 'key' denotes Q[i]. If the key exists in the array, return the index of the 'key', otherwise, return -1.

Note:

Can you solve each query in O(logN) ?