How to add bubblesort function to this current random number generator?

Question

Need to bubble sort 100 random numbers with range from -100 to 100 from high to low while maintaining the current decimal place precision. I have a bubble sort function but am not sure how to call it from within another function.

 #include "stdafx.h"
    #include <fstream>  // writing data to disk
    #include <cstdlib>  // standard general utilities library "# generator"
    #include <ctime>   // convert time value to string
    #include <iostream>
    #include <iomanip> // set precision

using namespace std;

// Functions
void number_Generator();

void bubbleSort (double *array, double length)
{
    int i,j;
    for (i=0;i<100;i++)
    {
        for (j=0;j<i;j++)
        {
            if(array[i]>array[j])
            {
                int temp = array[i];
                array[i]=array[j];
                array[j]=temp;
            }
        }
    }
}
int _tmain(int argc, _TCHAR* argv[])
{
    system("pause");
    cout.precision (6);
    number_Generator(); 
}

// Number Generator Function
void number_Generator()

{
    double Final_Avg = 0;

    double Random_Cap = 100;
    double Samples_To_Create = 100;
    srand((unsigned)time(0));
    double rndDbl;
    int rndInt;
    double rndAvg = 0, rndMin = 0, rndMax = 0;
    int counter = 0;
    double temp = 0;
    double dblRanAry[100]; 

    Final_Avg = rndAvg / counter; // final average to display

    double lDbl=0, hDbl=Random_Cap; 
    int lInt = 0, hInt=1;

    double dblRange=(hDbl-lDbl)+1;
    int intRange=(hInt-lInt)+1;

    for(int index=0; index<Samples_To_Create; index++) 
    {
    rndInt = lInt+int(intRange*rand()/(RAND_MAX + 1.0));
    rndDbl = lDbl+double(dblRange*rand()/(RAND_MAX + 1.0));

// random number if statement
if (rndInt == 0){
    rndDbl = -(rndDbl);

} //start of Min/Max if statements
if (rndMin == 0){
    rndMin = rndDbl;
}
else if (rndDbl < rndMin){
    rndMin = rndDbl;
}
if (rndMax == 0){
    rndMax = rndDbl;
}
else if (rndDbl > rndMax){
    rndMax = rndDbl;
} //end of Min Max if statements

temp = rndDbl;
rndAvg += temp;
dblRanAry[counter] = temp;
counter++;

cout.precision (6);
cout << fixed << " " << rndDbl << endl; 

}
cout << " " << endl
     << "The average = "  << fixed << rndAvg/counter << endl
     << " " << endl
     << "The Min = "  << fixed << rndMin << endl
     << " " << endl
     << "The Max = "   << fixed << rndMax << endl
     << " " << endl;

} // end of number generator function

Your sort code is given the argument `length` but it ignores it; you should probably use it. Don't you just call `bubbleSort(array, num_entries);` at the end of `number_Generator()` (where the variable names depend on how you implemented `number_Generator()`, of course. — Jonathan Leffler, Apr 20 '13 at 22:47

taocp · Accepted Answer · 2013-04-20T22:53:54.730

You need to do several things:

add the sort function call as shown below:

  int _tmain(int argc, _TCHAR* argv[])
  { 
       system("pause");
       cout.precision (6);

        int dblArray[100] = {0.0}; //these change are explained  below
        number_Generator(dblArray, 100); //100 means generate 100 random numbers
                  //remove double dblRanAry[100] inside the generator;
        bubbleSort (dblArray, 100) ;
  }

change the prototype of number_Generator to

 void number_Generator(double dblArray[], int length);

your number_Generator should either

return an array that stores those random numbers to main or
stores those numbers in a global array or
pass the array into it and stores numbers as I did above.

You may also change your number_Generator to meet the prototype change.

Additionally:

void bubbleSort (double *array, int length)
{                               //^^array length is int, not double
    for (int i = 0; i < length; i++)
    {               //^^use length, not hardcoded 100
        for (int j = 0; j < i; j++)
        {
            if(array[i] > array[j])
            {
                double temp = array[i];
                //since array elements are double, not int
                array[i] = array[j];
                array[j] = temp;
            }
        }
    }
}

how would you go about returning an array that stores those random numbers to main — Mac, Apr 20 '13 at 23:41
@Mac see this post? http://stackoverflow.com/questions/3473438/c-return-array-in-a-function — taocp, Apr 20 '13 at 23:42
@Mac simply loop over the dblArray in main and print them. `for (int i = 0; i < 100; ++i) { cout << dblArray[i] << " " ; }` after sorting. — taocp, Apr 21 '13 at 01:09

How to add bubblesort function to this current random number generator?

1 Answers1