CCC '08 J2 - Do the Shuffle - DMOJ: Modern Online Judge

CCC '08 J2 - Do the Shuffle

Points: 3

Time limit: 2.0s

Memory limit: 256M

Problem type

Canadian Computing Competition: 2008 Stage 1, Junior #2

Those tiny music machines that play your digital music are really computers that keep track of and play music files. The CCC music player (C³MP) is currently in development and will be hitting the stores soon! In this problem, you have to simulate a C³MP.

The C³MP music player will hold 5 songs in memory, whose titles will always be "A", "B", "C", "D" and "E". The C³MP also keeps track of a playlist, which is an ordering of all the songs. The C³MP has 4 buttons that the user will press to rearrange the playlist and play the songs.

Initially, the C³MP playlist is "A, B, C, D, E". The 4 control buttons do the following:

Button 1: move the first song of the playlist to the end of the playlist.
For example: "A, B, C, D, E" will change to "B, C, D, E, A".
Button 2: move the last song of the playlist to the start of the playlist.
For example, "A, B, C, D, E" will change to "E, A, B, C, D".
Button 3: swap the first two songs of the playlist.
For example, "A, B, C, D, E" will change to "B, A, C, D, E".
Button 4: stop rearranging songs and output the playlist.

You need to write a program to simulate a CCC music player. Your program should repeatedly ask for two positive integers $b$ ~b~ and $n$ ~n~. Here $b$ ~b~ represents the button number that the user wants to press, $1 \le b \le 4$ ~1 \le b \le 4~, and $n$ ~n~ represents the number of times that the user wants to press button $b$ ~b~. You can assume that $n$ ~n~ always satisfies $1 \le n \le 10$ ~1 \le n \le 10~.

The input will always finish with the pair of inputs ( $b = 4$ ~b = 4~, $n = 1$ ~n = 1~) when this happens, you should print the order of songs in the current playlist and your program should end. You can assume that the user will only ever press button 4 once.

Sample Input

Output for Sample Input

B C D A E

Explanation

(initial playlist is "A, B, C, D, E")
( $b = 2$ ~b = 2~, $n = 1$ ~n = 1~ so "A, B, C, D, E" changed to "E, A, B, C, D")
( $b = 3$ ~b = 3~, $n = 1$ ~n = 1~, so "E, A, B, C, D" changed to "A, E, B, C, D")
( $b = 2$ ~b = 2~, $n = 3$ ~n = 3~, so "A, E, B, C, D" changed to "B, C, D, A, E")
( $b = 4$ ~b = 4~, $n = 1$ ~n = 1~) When this happens, you should output the playlist.

Comments

1

QooModa commented on Feb. 22, 2022, 2:59 p.m.

Hi everyone!

Would like some tips on how to make my code more elegant.

For the output, used I printed a string created manually "iterating" each of the elements of the list I used to manipulate the list. But it looks very ugly.

Any other tips?

Thanks

3
Spitfire720 commented on Feb. 22, 2022, 3:04 p.m.
Your line to print the playlist can actually be shortened down thanks to a function in Python.

Instead of adding all the songs together, you can do this:

print(" ".join(playlist))

This will concatenate the strings with a space in between each string.

You can also check if the input is 4 instead of using a boolean.

0

keewanyayi288517 commented on Oct. 14, 2018, 1:19 a.m.

I think I will use an array

-38

andisong commented on Feb. 10, 2019, 1:34 p.m.

I tinky tink i vill uze a array too

This comment is hidden due to too much negative feedback. Show it anyway.

1

QiQi commented on Nov. 21, 2021, 2:52 a.m.

I think everyone used a array (arraylist included )or a list (depends on the language(s) you use).

2

dizmac commented on Nov. 21, 2021, 7:22 p.m. ← edited →

No, you can use an ArrayDeque as well.