Thread: sorting four numbers

I'm trying to take a users input and break it up into four separate numbers, then take those numbers and arrange them from smallest to largest.

So far I can't seem to get them working right, and i'm running out of ideas if anyone could give me an idea, or even a nudge in the right direction, I would greatly appreciate it.

Code:

# include <stdio.h>main ()
{
int inputVariables[4]; //where userinput goes after being broken up
int arrangedValues [4];// the user values arranged lowest to highest
int i;
int j;
int userInput;
int remainders; //used to break up input
int numberX; // users input arranged forwards
int numberY; // users input arranged forwards




printf ("Please state a number from 1000 - 9999, excluding numbers with four identical digits i.e 9999 \n");
scanf (" %d",&userInput);


remainders = userInput % 1000;
inputVariables[0] = userInput / 1000;
userInput = remainders;


remainders = userInput % 100;
inputVariables[1] = userInput / 100;
userInput = remainders;


remainders =userInput % 10;
inputVariables[2] = userInput / 10;
userInput = remainders;
inputVariables[3] = remainders;


printf ("%d \n",inputVariables[0]);
printf ("%d \n",inputVariables[1]);
printf ("%d \n",inputVariables[2]);
printf ("%d \n",inputVariables[3]);
printf ("%d \n", remainders);


do 
{


    for (i = 0 ; i < 4; i++)
    {
    for (j = 0 ; j < 4; j++)
        {
            if (inputVariables[i] < inputVariables[j])
            {
                arrangedValues[i] = inputVariables[j];    
            }
                
        }
    }
}    
while (arrangedValues[0] >= arrangedValues[1] >= arrangedValues[2] >= arrangedValues[3]);


printf(" %d %d %d %d \n",arrangedValues [0],arrangedValues [1],arrangedValues [2],arrangedValues [3]);
printf(" %d %d %d %d \n",arrangedValues [3],arrangedValues [2],arrangedValues [1],arrangedValues [0]);


}

I've been searching online and I found this code and it looks like it does what I want, and that I am not too far off, but I just can't wrap my head around how it works.

I went through it using a pen and paper (using the numbers 5 2 7, to walk through it) and I get to seven and I just can't wrap my head around what happens next.

Code:

void BubbleSort(int a[], int array_size)
{
     int i, j, temp;
     for (i = 0; i < (array_size - 1); ++i)
     {
          for (j = 0; j < array_size - 1 - i; ++j )
          {
               if (a[j] > a[j+1])
               {
                    temp = a[j+1];
                    a[j+1] = a[j];
                    a[j] = temp;
               }
          }
     }
}

if someone could at least explain how this works I can understand and adapt my own coding.

Originally Posted by Fear_Impurity

I've been searching online and I found this code and it looks like it does what I want, and that I am not too far off, but I just can't wrap my head around how it works.

I went through it using a pen and paper (using the numbers 5 2 7, to walk through it) and I get to seven and I just can't wrap my head around what happens next.

Code:

void BubbleSort(int a[], int array_size)
{
     int i, j, temp;
     for (i = 0; i < (array_size - 1); ++i)
     {
          for (j = 0; j < array_size - 1 - i; ++j )
          {
               if (a[j] > a[j+1])
               {
                    temp = a[j+1];
                    a[j+1] = a[j];
                    a[j] = temp;
               }
          }
     }
}

if someone could at least explain how this works I can understand and adapt my own coding.

I understand how the bubble sort concept works, but why does it require two loops, from going over the code, everything seems to happen only in the second loop.