SPOJ.com - Problem ADAQUEUE

ADAQUEUE - Ada and Queue

Ada the Ladybug has many things to do. She puts them into her queue. Anyway she is very indecisive, so sometime she uses the top, sometime the back and sometime she decides to reverses it.

Input

The first line consists of 1 ≤ Q ≤ 10⁶, number of queries. Each of them contains one of following commands

back - Print number from back and then erase it

front - Print number from front and then erase it

reverse - Reverses all elements in queue

push_back N - Add element N to back

toFront N - Put element N to front

All numbers will be 0 ≤ N ≤ 100

Output

For each back/front query print appropriate number.

If you would get this type of query and the queue would be empty, print "No job for Ada?" instead.

Example Input

15
toFront 93
front
back
reverse
back
reverse
toFront 80
push_back 53
push_back 50
front
front
reverse
push_back 66
reverse
front

Example Output

93
No job for Ada?
No job for Ada?
80
53
66

Submit solution!

Added by:	Morass
Date:	2016-09-06
Time limit:	3.5s
Source limit:	50000B
Memory limit:	1536MB
Cluster:	Cube (Intel G860)
Languages:	All except: ASM64 GOSU

hide comments

2016-12-22 17:57:27
For "TLE" :-
just think for reverse nothing else.
:)

2016-11-02 10:35:10 Sushovan Sen
I used only array for O(1) solution.

2016-10-23 14:26:06
can this be done "efficiently" without using linked list?

Last edit: 2016-10-23 21:37:28

2016-10-13 09:47:05 Sushovan Sen
@shubham_2324: O(1) solution possible for each query.

2016-09-27 19:10:30
Thanks! i got the problem but then also i am getting time limit exeeded while i am doing all operations in O(1) time except reverse which is taking O(n) , what to do.

2016-09-27 00:47:10
@shubham_2324: Generate a few test-cases and try to debug ;-)

Your program actually failed in function "reverse" in "while" cycle where the "current" pointer was equal "0".

But no clue what caused it :)

2016-09-26 18:57:56
i was getting time limit exeeded in python so i tried it in c with a queue of circular doubly linked list,now i am getting runtime error while my code is perfectly working on ideone.please help

2016-09-25 22:49:36
People have solved this in 0.01 seconds and I took 1 second. :/ Man there has to be some trick that I am unable to see at this point.

2016-09-10 15:56:08 Siu Ching Pong (Asuka Kenji)
@morass : Thanks! I just found where my bug is.

2016-09-10 15:50:56
@Siu Ching Pong (Asuka Kenji): toFront/push_back work as in "classical" queue, you just take the value (from input not from queue) and add it to front/end (no matter whether it is/isn't in queue).