SDE

Bob lives with his wife in a city named Berland. Bob is a good husband, so he goes out with his wife every Friday to ‘Arcade’ mall.

‘Arcade’ is a very famous mall in Berland. It has a very unique transportation method between shops. Since the shops in the mall are laying in a straight line, you can jump on a very advanced trampoline from the shop i, and land in any shop between (i) to (i + Arr[i]), where Arr[i] is a constant given for each shop.

There are N shops in the mall, numbered from 0 to N-1. Bob's wife starts her shopping journey from shop 0 and ends it in shop N-1. As the mall is very crowded on Fridays, unfortunately, Bob gets lost from his wife. So he wants to know, what is the minimum number of trampoline jumps from shop 0 he has to make in order to reach shop N-1 and see his wife again. If it is impossible to reach the last shop, return -1.

You have been given a number of stairs. Initially, you are at the 0th stair, and you need to reach the Nth stair.

Each time, you can climb either one step or two steps.

You are supposed to return the number of distinct ways you can climb from the 0th step to the Nth step.

Note:

Note: Since the number of ways can be very large, return the answer modulo 1000000007.

Example :

N=3

We can climb one step at a time i.e. {(0, 1) ,(1, 2),(2,3)} or we can climb the first two-step and then one step i.e. {(0,2),(1, 3)} or we can climb first one step and then two step i.e. {(0,1), (1,3)}.

You are given two LinkedList of length ‘N’. Your task is to insert the elements of the second LinkedList in the first LinkedList at the alternate positions.

For example: Let 1 -> 3 -> 5 be the first LinkedList and 2 -> 4 -> 6 be the second LinkedList. Then after merging the first LinkedList will look like 1 -> 2 -> 3 -> 4 -> 5 -> 6.