Cpp > Programs

cpp vector example 4

#include <iostream>
#include <vector>
using namespace std;

typedef vector<int> intVector;

template<class T, class A>
void ShowVector(const vector<T, A>& v);
template<class T, class A>
void compareVectors(const vector<T, A>& v1, const vector<T, A>& v2);

int main()
{
intVector vInt1(5); // define a vector of integers with 5 elements
cout << "vInt1(5)" << "\n";

// assign a value to each element in vInt using subscripts
for (vector<int>::size_type i = 0; i < vInt1.size(); ++i) {
vInt1[i] = 5 * i;
}
ShowVector(vInt1);

intVector vInt2 = vInt1; // define a vector vInt2 and
// copy elements from vInt1
cout << "vInt2(5)" << "\n";
ShowVector(vInt2);

// compare vInt and vInt2
compareVectors(vInt1, vInt2);

// add an element at the end of vInt2
cout << "vInt2 after push_back()\n";
vInt2.push_back(100);
ShowVector(vInt2);

// compare vInt and vInt2 again
compareVectors(vInt1, vInt2);

// now swap vInt and vInt2
vInt1.swap(vInt2);
cout << "vInt1 after swap\n";
ShowVector(vInt1);
cout << "vInt2 after swap\n";
ShowVector(vInt2);
compareVectors(vInt1, vInt2);

return 0;
}

//
// Display vector properties
//
template<class T, class A>
void ShowVector(const vector<T, A>& v)
{
cout << "size() = " << v.size() << "\tcapacity() = " << v.capacity() << "\n";

// display vector elements using subscripts
cout << "elements:\t";
for (vector<T, A>::size_type i = 0; i < v.size(); ++i)
cout << v[i] << ", ";
cout << "\n\n";
}

//
// Compare two vectors
//
template<class T, class A>
void compareVectors(const vector<T, A>& v1, const vector<T, A>& v2)
{
if (v1 == v2) {
cout << "v1 == v2";
}
else if (v1 < v2)
{
cout << "v1 < v2";
}
else
{
cout << "v1 > v2";
}
cout << "\n\n";
}