Question

Array based application

#include <iostream>
#include <string>
#include <fstream>
using namespace std;

// Function prototypes
void selectionSort(string [], int);
void displayArray(string [], int);
void readNames(string[], int);

int main()
{
   const int NUM_NAMES = 20;
   string names[NUM_NAMES];

   // Read the names from the file.
   readNames(names, NUM_NAMES);

   // Display the unsorted array.
   cout << "Here are the unsorted names:\n";
   cout << "--------------------------\n";
   displayArray(names, NUM_NAMES);

   // Sort the array.
   selectionSort(names, NUM_NAMES);

   // Display the sorted array.
   cout << "\nHere are the names sorted:\n";
   cout << "--------------------------\n";
   displayArray(names, NUM_NAMES);

   return 0;
}

// ********************************************************
// The selectionSort function performs an ascending order *
// selection sort on an array of strings. The size *
// parameter is the number of elements in the array. *
// ********************************************************
void selectionSort(string values[], int size)
{
   int startScan;
   int minIndex;
   string minValue;

   for (startScan = 0; startScan < (size - 1); startScan++)
   {
       minIndex = startScan;
       minValue = values[minIndex];

       for(int index = startScan + 1; index < size; index++)
       {
           if (values[index] < minValue)
           {
               minValue = values[index];
               minIndex = index;
           }
       }

       values[minIndex] = values[startScan];
       values[startScan] = minValue;
   }
}

// ********************************************************
// The displayArray function displays the contents of *
// the array. *
// ********************************************************
void displayArray(string values[], int size)
{
   for (int i = 0; i < size; i++)
       cout << values[i] << endl;
}

// ********************************************************
// The readNames function reads the contents of the *
// "names.dat" file into the array. *
// ********************************************************
void readNames(string values[], int size)
{
int index = 0;   // Array index

// Open the file.
ifstream inFile;
inFile.open("names.dat");

// Test that the file was opened.
if (!inFile)
{
cout << "Error opening names.dat\n";
exit(0);
}

   // Read the names from the file into the array.
while (index < size)
{
// Get a line from the file.
       getline(inFile, values[index]);

// Increment index.
index++;
}

// Close the file.
inFile.close();

Program 1:

Use the array based application above to build an equivalent STL Vector application. Keep in mind that a vector object can be passed to functions like any other object, it is not an array.

Use the following as the input data for the names.dat file.

Collins, Bill
Smith, Bart
Allen, Jim,
Griffin, Jim
Stamey, Marty
Rose, Geri,
Taylor, Terri
Johnson, Jill,
Allison, Jeff
Looney, Joe
Wolfe, Bill,
James, Jean
Weaver, Jim
Pore, Bob,
Rutherford, Greg
Javens, Renee,
Harrison, Rose
Setzer, Cathy,
Pike, Gordon
Holland, Beth

Answer 1

Hi

I have updated the code vector and it is working fine.

#include <iostream>
#include <vector>
#include <fstream>
#include <cstdlib>
using namespace std;
// Function prototypes
void selectionSort(vector<string> &, int);
void displayArray(vector<string> &, int);
void readNames(vector<string> &);
int main()
{
vector<string> names;
// Read the names from the file.
readNames(names);
// Display the unsorted array.
cout << "Here are the unsorted names:\n";
cout << "--------------------------\n";
displayArray(names, names.size());
// Sort the array.
selectionSort(names, names.size());
// Display the sorted array.
cout << "\nHere are the names sorted:\n";
cout << "--------------------------\n";
displayArray(names, names.size());
return 0;
}
// ********************************************************
// The selectionSort function performs an ascending order *
// selection sort on an array of strings. The size *
// parameter is the number of elements in the array. *
// ********************************************************
void selectionSort(vector<string>& values, int size)
{
int startScan;
int minIndex;
string minValue;
for (startScan = 0; startScan < (size - 1); startScan++)
{
minIndex = startScan;
minValue = values[minIndex];
for(int index = startScan + 1; index < size; index++)
{
if (values[index] < minValue)
{
minValue = values[index];
minIndex = index;
}
}
values[minIndex] = values[startScan];
values[startScan] = minValue;
}
}
// ********************************************************
// The displayArray function displays the contents of *
// the array. *
// ********************************************************
void displayArray(vector<string>& values, int size)
{
for (int i = 0; i < size; i++)
cout << values[i] << endl;
}
// ********************************************************
// The readNames function reads the contents of the *
// "names.dat" file into the array. *
// ********************************************************
void readNames(vector<string>& values)
{
// Open the file.
ifstream inFile;
inFile.open("names.dat");
string name;
// Test that the file was opened.
if (!inFile)
{
cout << "Error opening names.dat\n";
exit(0);
}
// Read the names from the file into the array.
while (!inFile.eof())
{
// Get a line from the file.
getline(inFile,name);
values.push_back(name);
// Increment index.

  
}
// Close the file.
inFile.close();

}

Output:

sh-4.2$ g++ -o main *.cpp                                                                                                                                                                                                                                                

sh-4.2$ main                                                                                                                                                                                                                                                             

Here are the unsorted names:                                                                                                                                                                                                                                             

--------------------------                                                                                                                                                                                                                                               

Collins, Bill   

Smith, Bart   

Allen, Jim,   

Griffin, Jim

Stamey, Marty   

Rose, Geri,

Taylor, Terri

Johnson, Jill,   

Allison, Jeff   

Looney, Joe

Wolfe, Bill,

James, Jean

Weaver, Jim

Pore, Bob,

Rutherford, Greg

Javens, Renee,

Harrison, Rose

Setzer, Cathy,   

Pike, Gordon

Holland, Beth   

Here are the names sorted:                                                                                                                                                                                                                                               

--------------------------                                                                                                                                                                                                                                               

Allen, Jim,   

Allison, Jeff   

Collins, Bill

Griffin, Jim                                                                                                                                                                                                                                                             

Harrison, Rose                                                                                                                                                                                                                                                           

Holland, Beth                                                                                                                                                                                                                                                            

James, Jean                                                                                                                                                                                                                                                              

Javens, Renee,                                                                                                                                                                                                                                                           

Johnson, Jill,                                                                                                                                                                                                                                                           

Looney, Joe                                                                                                                                                                                                                                                              

Pike, Gordon                                                                                                                                                                                                                                                             

Pore, Bob,                                                                                                                                                                                                                                                               

Rose, Geri,                                                                                                                                                                                                                                                              

Rutherford, Greg                                                                                                                                                                                                                                                         

Setzer, Cathy,                                                                                                                                                                                                                                                           

Smith, Bart                                                                                                                                                                                                                                                              

Stamey, Marty                                                                                                                                                                                                                                                            

Taylor, Terri                                                                                                                                                                                                                                                            

Weaver, Jim                                                                                                                                                                                                                                                              

Wolfe, Bill,