Help with Selection Sort for vectors and arrays

[asundar]

Hey everyone,

So, I need help understanding why I'm not able sort my code: here is my code (so far) for my selection sort. I have only written the iterative form of Selection Sort, but I know how to do it recursively as well (which is required for my homework). When I print it out, it just prints out the unsorted array AFTER I call the selection sort. Here is my full code so far:

main.cpp

#include <iostream>
#include <vector>
#include <cstdlib>
#include <ctime>
#include "SelectionSort.h"

using namespace std;

template <class print> void printData(print a, int sizeOf);
template <class randomData> void putData(randomData a,int sizeOf);
void createCopy (int a[], int b[], const int size);

int main()
{
    const int smallSize = 20;
    const int largeSize = 5000;

    int smallArray[smallSize];
    vector <int> smallVector(smallSize);
    int largeArray[largeSize];
    vector <int> largeVector(largeSize);

    putData(smallArray,smallSize);
    putData(largeArray,largeSize);

    putData<vector <int>&>(smallVector,smallVector.size());
    putData<vector <int>&>(largeVector,largeVector.size());

    int copySmallArr[smallSize];
    vector<int> copySmallVec(smallSize);
    int copyLargeArr[largeSize];
    vector<int> copyLargeVec(largeSize);

    createCopy(copySmallArr,smallArray,smallSize);
    copySmallVec = smallVector;
    createCopy(copyLargeArr,largeArray,largeSize);
    copyLargeVec = largeVector;

    cout << "\nSmall Array Unsorted: ";
    printData(smallArray,smallSize);

    cout << "\nSmall Vector Unsorted: ";
    printData<vector <int>&>(smallVector,smallVector.size());

    SelectionSort sort;
    sort.sortDataIter(smallArray,smallSize);
    cout << "\nSmall Array Sorted: ";
    printData(smallArray,smallSize);

    sort.sortDataIter(smallArray,smallSize);
    cout << "\nSmall Vector Sorted: ";
    printData(smallVector,smallVector.size());

    return 0;
}

void createCopy (int a[], int b[], const int size)
{
    for(int i = 0; i < size; i++)
    {
        a[i] = b[i];
    }
}

template <class randomData>
void putData(randomData a, int sizeOf)
{
    srand((unsigned int)time(0));

    for(int i = 0; i < sizeOf; i++)
    {
        a[i] = rand()%1000;
    }
}

template <class print> 
void printData(print a,int sizeOf)
{
    for(int i = 0; i < sizeOf; i++)
    {
        cout << a[i] << " ";
    }
    cout << endl;
}

SelectionSort.h

#include <iostream>

using namespace std;

class SelectionSort
{
public:
    void sortDataIter(int theList[], int sizeOfList);
    void sortDataIter(vector<int>& theList, int sizeOfList);
    void sortDataRec (vector<int>& theList, int sizeOfList,int min);
    void sortDataRec (int theList[], int sizeOfList,int min);
    void swap(int one, int two);
};

SelectionSort.cpp

#include <iostream>
#include <vector>
#include <cstdlib>
#include <ctime>
#include "SelectionSort.h"

using namespace std;

void SelectionSort :: sortDataIter (int theList[], int sizeOfList)
{
    for(int i = 0; i < sizeOfList-1; i++)
    {
        int min = i;
        for(int j = i+1; j<sizeOfList;j++)
        {
            if (theList[j] < theList[min])
            {
                min = j;
            }
        }
        swap(theList[i],theList[min]);
    }
}

void SelectionSort :: sortDataIter (vector<int>& theList, int sizeOfList)
{
    int min = 0;
    for(int i = 0; i < sizeOfList-1; i++)
    {
        min = i;
        for(int j = i+1; j<sizeOfList;j++)
        {
            if (theList[j] < theList[min])
            {
                min = j;
            }
        }
        swap(theList[min],theList[i]);
    }
}


void SelectionSort :: sortDataRec (int theList[], int sizeOfList,int min)
{
}

void SelectionSort :: sortDataRec (vector<int>& theList, int sizeOfList,int min)
{
}


void SelectionSort :: swap(int one, int two)
{
    int temp = one;
    one = two;
    two = temp;
}

[tinstaafl]

Your algorithms seem to be ok, the problem appears to be in the swap. You're only swapping the values not the elements of the collection itself. See if this helps:

void SelectionSort :: swap(int& one, int& two)
{
    int temp = one;
    one = two;
    two = temp;
}