How Would I Implement the Insertion Sort With Pointer Arrays?

Question

Okay, so I have a homework assignment to sort pointer arrays using two different sorts that are buried in functions. I BELIEVE I know how to implement the bubble sort, but I'm just really having trouble understanding what I have to do without using STL containers. Here's what I have already:

#include <iostream>
#include <string>
#include <iomanip>
#include <conio.h>
#include <cstdlib>
#include <fstream>
#include <iostream>
#include <cstring>
using namespace std;



//Enumeration
enum columns{SSN=0, LASTNAME=1};

//Global Constants
const int MAXELEMENTS = 100;

void insertionSort (string* [2][MAXELEMENTS], int);

int main ()
{

int index = 0;
int elemCnt = 0;
string employee_array[2][MAXELEMENTS];
string * p2employee_array [2] [MAXELEMENTS] = {{NULL}};
fstream inFile;


inFile.open("Lab4.csv", ios::in);
if (inFile.fail())
{
    cout<<"File Failed To Open"<<endl;
}

while(!inFile.eof())
{
    //Load the values array
    getline(inFile,employee_array[LASTNAME][index],',');
    getline(inFile,employee_array[SSN][index],'\n');

    //Load the pointers array
    p2employee_array[LASTNAME][index] = &employee_array[LASTNAME][index];
    p2employee_array[SSN][index] = &employee_array[SSN][index];
    elemCnt++;
    index++;
}

inFile.close();
if (inFile.fail())
{
    cout<<"File Failed To Close"<<endl;
}

//Construct a separator line
string line;
line = line.assign(64,'-');

//Display the original data
cout << "ORIGINAL DATA..." << endl << endl;
cout << setw(40) << "Employee Data" << endl
     << setw(40) << "Adrian Rodriguez" << endl << endl << endl;
cout << left << setw(40) << " " << setw(12) << "Address of" << "Address of"
     << endl
     << setw(20) << "SSN"
     << setw(20) << "Last Name" << setw(12) << "SSN" << "Last Name"
     << endl;
cout << line << endl << endl;

elemCnt = elemCnt;

for(index = 0; index<elemCnt; index++)
{
    cout << setw(20) << employee_array[SSN][index]
         << setw(21) << employee_array[LASTNAME][index]
         << setw(12) << p2employee_array[SSN][index]
         << setw(12) << p2employee_array[LASTNAME][index]
         << endl;
}
cout<<endl<<endl;
cout<<"About to sort arrays of pointers in ASCENDING ORDER on LAST NAME..."<<endl;


insertionSort (p2employee_array, elemCnt);
getch ();
return 0;
 }

 //************************************************

void insertionSort (string* p2employee_array, int elemCnt)
{
int j;
char* cmp; // cmp is a pointer to a C string
for( int i = 1; i < size; ++i )
{
cmp = (char*)p2employee_array[i].c_str();//pointer in cmp
j = i - 1;

while(j>=0 && strcmp(cmp,p2employee_array[j].c_str())<0)
{
  p2employee_array[j + 1] = p2employee_array[j]; 
    --j;
}
 p2employee_array[j + 1] = string(cmp); // insert
}

My code will not build a file and this is driving me crazy. Can somebody please tell me what I'm doing wrong?? The error message just says : undefined reference to `insertionSort(std::string* (*) [100], int)

Answer 1

The forward declaration is this:

void insertionSort (string* [2][MAXELEMENTS], int);

But the definition is this:

void insertionSort (string* p2employee_array, int elemCnt)
{
    ...
}

The function signatures need to match. ie

void insertionSort (string* p2employee_array[2][MAXELEMENTS], int elemCnt)
{
    ...
}