SDE - 1

Once Kevin is playing a hurdle game in which he has to jump some hurdles to clear a particular level. Each level ‘i’ has ‘i’ hurdles (for example, level 6 has 6 hurdles).

You are provided with the total number of hurdles that Kevin has jumped, you have to tell how many levels he has cleared.

Note :

Kevin has played this game once. He can only reach the level ‘i’ if and only if he has already cleared the level (‘i’ - 1).

You are given an integer 'N'. For a given 'N' x 'N' chessboard, find a way to place 'N' queens such that no queen can attack any other queen on the chessboard.

A queen can be killed when it lies in the same row, or same column, or the same diagonal of any of the other queens. You have to print all such configurations.

Bob has been given a triangular pyramid with its vertices marked as ‘O’, ‘X’, ‘Y’ and ‘Z’ and provided with another integer ‘N’. In a single step, Bob can go to any adjacent vertices. Bob will always start from ‘O’ and has to return to ‘O’ after making exactly ‘N’ steps.

Your task is to find out the number of ways he can take to complete his journey.

Note :

As the answer can be very large, return the answer by taking modulo with 1000000007.

For example :

If ‘N’=1 
So in 1 step we can reach either to ‘X’ , ‘Y’ or ‘Z’ and can not travel back to ‘O’.
Thus there are 0 ways.

If ‘N’ =2
So there are total three ways :
(i)  O->X->O
(ii) O->Y->O
(iii) O->Z->O

If ‘N’ = 3
So there are total 6 ways :
(i) O->X->Y->O
(ii) O->X->Z->O
(iii) O->Y->X->O
(iv) O->Y->Z->O
(v) O->Z->X->O
(vi) O->Z->Y->O

You have been given an integer 'N'. Your task is to generate and return all binary strings of length 'N' such that there are no consecutive 1's in the string.

A binary string is that string which contains only ‘0’ and ‘1’.

For Example:

Let ‘N'=3, hence the length of the binary string would be 3. 

We can have the following binary strings with no consecutive 1s:
000 001 010 100 101 

You are given three strings “A”, “B” and “C”. Your task is to check whether “C” is formed by an interleaving of A and B. C is said to be interleaving “A” and “B”, if the length of “C” is equal to the sum of the length of A and length of B, all the characters of “A” and “B” are present in “C”, and the order of all these characters remains the same in all three strings.

For Example:

If A = “aab”, B = “abc”, C = “aaabbc”
Here C is an interleaving string of A and B. Because C contains all the characters of A and B and the order of all these characters is also the same in all three strings.

If A = “abc”, B = “def”, C = “abcdefg”
Here C is not an interleaving string of A and B as neither A nor B contains the character ‘g’.

Ninja has been given 2 points ‘A’ and ’B’ that corresponds to the line ‘AB’ and ‘P’, ’Q’ that corresponds to line ‘PQ’ on a 2D plane. Ninja wants to find the intersection point of the ‘AB’ and ‘PQ’ lines up to 6 decimal places. If there is no such intersection point print -1.000000 -1.000000.

Note:

1. You do not need to fix the output up to 6 decimal places. it has already been taken care of. Just return the output in the data type mentioned in the function. 
2. Lines ‘AB’ and ‘PQ’ are two different lines. 

For Example: For A(0, 3), B(3, 0) and P(0, 0), Q(5, 5) the point of intersection of line ‘AB’ and ‘PQ’ is (1.500000, 1.500000). As shown below:

As Ninja is weak in Geometry, can you help him to find the intersection of these two lines?

Given a directed graph, check whether the graph contains a cycle or not. Your function should return true if the given graph contains at least one cycle, else return false.

Started with spring beans, functional dependencies and asked how will check dependencies are valid or not. When I said they must be in the form of a directed acyclic graph. Then he asked me to check whether there exists a cycle or not.

How does URL work and What is a load balancer.