Assistant System Engineer

1. Inheritance
2. Abstraction
3. Interface
4.Method overloading and overriding
Encapsulation

1. Print a given string by reversing each of it's words.
2. State the difference between StringBuffer and StringBuilder in Java.
3. What is the difference between str1 == str2 and str1.equals(str2)?

You are given an integer ‘N’, your task is to find and return the N’th Fibonacci number using matrix exponentiation.

Since the answer can be very large, return the answer modulo 10^9 +7.

Fibonacci number is calculated using the following formula:

F(n) = F(n-1) + F(n-2), 
Where, F(1) = F(2) = 1.

For Example:

For ‘N’ = 5, the output will be 5.

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.

1. MySQL query to find out last 10 records.
2. inner join
3. Outer join