Software Engineer

Given a string ‘STR’ containing lowercase and uppercase letters. You need to sort the string so that the resulting string contains uppercase and lowercase letters at alternate positions but in sorted order.

Note

If any lowercase or uppercase letters remains left after alternate positioning, then append them at the last of the string in sorted order.

For Example

If the given string STR = “rDaBfS” then after sorting  STR = “aBfDrS”. In the sorted string, lowercase letters a,f,r, and uppercase letters B, D, S are in sorted order and alternate positions.

You are given a string consisting only of parentheses and letters. Your task is to remove the minimum number of invalid parentheses and return all possible unique, valid strings thus obtained.

Note:

1) A string is valid only if every left parenthesis has corresponding right parentheses in the same order.

For example Given ‘STR’ = (())()) is not a valid string, whereas ‘STR’ = (())() is a valid string.

The n-th term of Fibonacci series F(n), where F(n) is a function, is calculated using the following formula -

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

Provided 'n' you have to find out the n-th Fibonacci Number. Handle edges cases like when 'n' = 1 or 'n' = 2 by using conditionals like if else and return what's expected.

"Indexing is start from 1"

Example :

Input: 6

Output: 8

Explanation: The number is ‘6’ so we have to find the “6th” Fibonacci number.
So by using the given formula of the Fibonacci series, we get the series:    
[ 1, 1, 2, 3, 5, 8, 13, 21]
So the “6th” element is “8” hence we get the output.

You are given a non-negative integer 'K'. Your task is to find out the Kth row of Pascal’s Triangle.

In Mathematics, Pascal's triangle is a triangular array where each entry of a line is a value of a binomial coefficient. An example of Pascal’s triangle is given below.

Example :-

INPUT : K = 2
OUTPUT: 1 1

In the above example, K = 2, Hence the 2nd row from the top of pascal’s triangle, as shown in the above example is 1 1.

INPUT   : K = 4
OUTPUT  : 1 4 6 4 1

In the above example, K = 4, Hence the 4th row from the top of pascal’s triangle, as shown in the above example is 1 3 3 1.