SDE - 1

You are given a string STR of length N consisting of lowercase English Alphabet letters. Your task is to return the count of minimum characters to be added at front to make the string a palindrome.

For example:

For the given string “deed”, the string is already a palindrome, thus, minimum characters needed to be added are 0. 

Similarly, for the given string “aabaaca”, the minimum characters needed are 2 i.e. ‘a’ and ‘c’ which makes the string “acaabaaca”, which is a palindrome.   

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 ]   ]

Design system to store telephone directory details

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.

Design red bus

design type ahead suggestion

what is multi tenant system