Stuck on creating a separate function for bubble sort

[markat]

Hello,

I've been charged with the following task:
•Write a program that:
•1) Creates an array containing 1000 random double numbers in the [0,250) range;
•2) Sorts them in ascending order;
•3) Prints the contents of the sorted vector out. The sorting should be coded as a separate function double* sort_array(double* ).

I had gotten stuck and referred to help from other forum postings, but I'm still having trouble. I'm not quite sure how to put the sorting in another function. I tried, but if anyone can point out what I did wrong, your help is greatly appreciated. With the following code, I'm currently getting the error messages:
line 41: error: unexpected '(' for function style cast or type construction
line 41: error: use of undeclared identifier 'MyArray'

#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;

//program to sort array
double* sort_array(double* MyArray)
{
        //Bubblesort code in ascending order
        double size =1000;
        int a, b, t;
        for (a=1; a<size; a++) {     //
            for (b=size-1; b>=a; b--) {     //
                if (MyArray [b-1] > MyArray [b]) { //if not in ascending order
                //exchange elements
                t = MyArray [b-1];  //use t as a placeholder so original value of MyArray [b-1] is not lost
                MyArray [b-1] = MyArray [b]; //change value of MyArray [b-1] to value of MyArray [b]
                MyArray [b] = t; //change value of MyArray[b] to value of placeholder aka original value of MyArray [b-1]
                }
            }
        }
    return MyArray; //returns sorted values
}

//main program, creates array
int main()
{
    srand(time(NULL)); //generate random numbers based on time

    int t;
    double size = 1000;

    double unsort[1000];  //creates array of 1000 double values
        for (t=0; t<size; ++t)  //check boundaries, use size for 1000
        {
            unsort[t] = (double)(rand()%251); //assign random double numbers between [0,250]
            cout << unsort[t] << " ";   //print unsorted values
        }
        cout << "\n" << endl;
        sort_array(double* MyArray);

        for (t=0; t<size; t++){
            cout << unsort[t];
        }
    return 0;
}  

Time is of the essence, so thank you in advance for any quick suggestions!

[anup30]

#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;

//program to sort array
void sort_array(double MyArray[], int size) ////////////////void
{
        //Bubblesort code in ascending order
        /////double size =1000;
        int a, b, t;
        for (a=1; a<size; a++) 
		{     //
            for (b=size-1; b>=a; b--) 
			{     //
                if (MyArray [b-1] > MyArray [b]) 
				{ //if not in ascending order
                //exchange elements
                t = MyArray [b-1];  //use t as a placeholder so original value of MyArray [b-1] is not lost
                MyArray [b-1] = MyArray [b]; //change value of MyArray [b-1] to value of MyArray [b]
                MyArray [b] = t; //change value of MyArray[b] to value of placeholder aka original value of MyArray [b-1]
                }
            }
        }
    //////return MyArray; //returns sorted values
}

//main program, creates array
int main()
{
    srand(time(NULL)); //generate random numbers based on time

    int t;
    double size = 1000;

    double unsort[1000];  //creates array of 1000 double values
        for (t=0; t<size; ++t)  //check boundaries, use size for 1000
        {
            unsort[t] = (double)(rand()%251); //assign random double numbers between [0,250]
            cout << unsort[t] << " ";   //print unsorted values
        }
        cout << "\n\n\n\n\n\n" << endl;

        sort_array(unsort, size); //////////////////

        for (t=0; t<size; t++)
		{
            cout << unsort[t] << " ";
        }
    return 0;
}  

notice that rand() gives you integers, you have program to generate doubles.

[markat]

Thanks! It's running now, but I'm still having trouble getting it to print out the values. I was thinking I might try to have it print the unsorted values first, and then print out the sorted values, but I could just have it do the sorted ones.

Any suggestions?

[markat]

Nevermind, figured it out! It was simply an issue of where I had saved the file.

Thanks for your help, anup30!

[anup30]

one thing, x = [a,b) means a<= x < b

so, randoms < 250 ---> rand()%250

notice, your home work,

1000 random double numbers

not ints as in the example!

[markat]

Oh you're right, that was careless reading on my part. I'll change the interval to 250.

I'll try to find a way to randomly generate doubles instead of ints.

Thanks!