Homework Help!!!!!

i need code that will arrange a 4 digit number into descending order, for example if...


int x;
cout<<"enter 4 digit number<<endl;
cin>>x;
*// here's where i need to have the program arrange the 4 digit number into descending order...

any help would be greatly appreciated!! thanks!! :cool:

Welcome to the forums bcianfrocca, As far as doing h/w, c´mon, you really need to give it a try, and when you run into a problem then ask a specific question. Hey, if you really want to be a programmer, you need to learn this stuff.
Hope that helps.
-d-

do u mean..

if user enter 7689


it has to be arranged as 9876

[edit]
And I dont think you will get homework help here unless you put in some effort..
[/edit]

Heres the best way to get help..

Try to make a program.. If it doesnt work as you expected, look over your code very carefully. Go through it as your computer would saying outloud what each step is doing. If you do that and still cant figure it out, post your code, then you will get some hints on things to try.

That way your not hurting yourself by having someone do the work for you.

i am doing my own work, the program is alot bigger than this, but i am stuck on this part only, i've tried alot of different function calls for this, and nothing is working... i just need to get over this little hiccup and proceed with the rest of the program, but i can't until i figure out how to do this...

Hmm, the only way that I know of, would be to have the user input it as a string. Then you could break the string up and rearrange them and print them back out.

that's what i thought too, but would i have to do something like this...

char mystring [1] =
char mystring [2] =
char mystring [3] =

and so on so forth...?? and if so, how would the program be able to distinguish which digit is the highest of the 4?

i.e. to arrange 3748 to 8743..?? this is confusing!!

Using conditionals. To be honest bcianfrocca, I doubt this is a much larger project if you do not understand the uses for conditionals. Try some code yourself.

You could do something like this.

Code:

---

// Create a string
char num_string[4];

// get user input into the string "cin >> num_string;"

// break the string into smaller parts and convert them to ints
int num1 = atoi(num_string[0]);

// check each number keeping track of which is larger - Use some ifs and > < signs

// Create a separate string to hold the result - (you could use itoa() to convert them back to chars.

// and print them out.

---

This should be enough for you to make a nearly running program. I dont want to give you complete code because you really need to figure out the majority for yourself.

thanks for the help guys, but you all don't have to be so mean about it, this is only my 2nd semester in C++ and i'm new to all this, take it easy on me, geesh...

:) , I wasnt mean about it. Er, I didnt mean to come across mean rather.

We are saying "Do it yourself" not in a mean way. We say it because it wouldn't help you at all if we gave you the answer. It would hurt you actually.

I know it sounds mean but since its internet its hard to tell the posters real intentions.

Just know that I wasnt mean at all :)

I really don't mean this in a mean way, so I apologize if you are offended by this, but I am trying to help you. People on this board get very ........ed of when people do several things:

1) Come to us with homework, or insult our inteligence (our egos are feeble as it is) by saying it's not homework when it's Sunday night, you just joined the board, and you offer no evidence otherwise. In short, when people expect us to do the work for them.

2) Don't use code tags (you didn't do a huge job of ignoring this one, but just for future reference)

3) Don't use google (again)

I would suggest reading the announcements and stickies at the top of the forum. They'll explain all of this in detail.

>but you all don't have to be so mean about it
Here, I'll be nice and give you the entire solution:

Code:

---

#include <cctype>
#include <cstdlib>
#include <algorithm>
#include <iostream>
#include <string>

bool is_valid ( std::string num )
{
  typedef std::string::const_iterator c_iter;

  if ( num.size() != 4 )
    return false;

  for ( c_iter it = num.begin(); it != num.end(); ++it ) {
    if ( !isdigit ( static_cast<unsigned char> ( *it ) ) )
      return false;
  }

  return true;
}

int main()
{
  std::string num;

  std::cout<<"Enter a 4 digit number: ";

  if ( std::getline ( std::cin, num ) ) {
    if ( is_valid ( num ) ) {
      std::sort ( num.rbegin(), num.rend() );
      std::cout<< num <<std::endl;
    }
    else {
      std::cerr<<"Invalid input"<<std::endl;
      return EXIT_FAILURE;
    }
  }
  else {
    std::cerr<<"Input error"<<std::endl;
    return EXIT_FAILURE;
  }

  return EXIT_SUCCESS;
}

---

Of course, I can't guarantee that if you turn it in your teacher will accept it, this being only your second semester and all. :) So you will still have to do your own work, this code is designed to give you a starting point. And it's designed to get you a failing grade if you turn it in based on some subtle techniques that require advanced knowledge of C++. So unless you learn enough to know what I did and why and can explain it in detail if approached with a plegiarism accusation, I suggest you study the code for concepts and use those concepts to work through your own solution.

good old fashoned c code:

Code:

---

#include <stdio.h>

void main(void)
{
        char char1,char2,char3,cahr4;
        scanf("%c%c%c%c",char1,char2,char3,char4);
        printf("%c%c%c%c",char4,char3,char2,char1);
}

---

Lol, Prelude, how do you do that...

You gave the whole answer.. yet.. you didnt. Amazing.

actually the project is due 2 weeks from now, and i am trying to learn this stuff as fast as i can, i don't want the entire solution to a problem, i just came to this forum to get tidbits of help to help me over things that i can't find in my books or online anywhere else, i know noone else that does C++ code, so i figured i would come here and get some help. and if i don't come to you guys with homework questions, then what other types of questions are there?? if i'm in at my job doing programming, i'm not gonna need anyone else's help. anyways, thanks alot for the help, and "prelude", thanks for tryin, but that code is WAY over my head right now... and to you "sean mackrory", eat a xanax and chill out brotha...

djz3r0 - you're assuming the numbers are entered in ascending order. This will rarely be the case.

>good old fashoned c code
Maybe old fashioned, but certainly not good.

>void main(void)
Don't make me switch to ANSI nazi mode. main returns int, it always has.

>char char1,char2,char3,cahr4;
Check your spelling, or write enough C code so that you're physically unable to misspell char. ;)

>scanf("%c%c%c%c",char1,char2,char3,char4);
Eew. I say again, eew. First and foremost you need to use the ampersand in all of those charN's because scanf expects a pointer. Second, you need to check the return value of scanf because users can't follow directions (especially since you didn't give any in this program).

>printf("%c%c%c%c",char4,char3,char2,char1);
Okay, this is assuming that the characters are entered in ascending sorted order to begin with. I don't recall the OP mentioning that particular requirement. In fact, I can remember a specific example that suggests that the digits will be in random order, so your code is broken even if you fix it. :rolleyes:

alright, well thanks for the help i guess, "prelude", your dorkness far exceeds mine, and i mean that as a compliment, lol... i can't understand any of that code, yet, but alot of the other users have helped, thanks alot guys, i appreciate it :D

>"prelude", your dorkness far exceeds mine, and i mean that as a compliment
I'll take it as a compliment. ;)

>i can't understand any of that code
That was the point really. We're glad to help with your C++ problems, provided you can prove that you've given it an honest attempt. If you have an idea of how to go about it, run it by us and we'll offer suggestions. But a request for code that solves your problem doesn't go over well, and you'll either get stoney silence, flames, or extreme sarcasm for your trouble.

Hint:
Read the number as a char array. That gets it into a form that will make it easy to sort. And if you don't know how to use arrays (as your earlier post demonstrates), I suggest you read up on them (there's a tutorial on this site).

**EDIT**
Sorry Vicious, should've read the rest of the thread more carefully.