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Vector Class Examples
3. Iterators
% cat vecT.cpp
// vector<T> example 2
#include <iostream>
using namespace std;
#include <vector>
int main()
{
vector<int> intVec;
intVec.push_back(7);
intVec.push_back(2);
intVec.push_back(8);
intVec.push_back(3);
cout << "Display using subscript notation:\n";
for (int i = 0; i < intVec.size(); i++)
{
cout << intVec[i] << " ";
}
// iterator notation
cout << "\n\nDisplay using iterator notation:\n";
vector<int>::iterator vecIter = intVec.begin();
while(vecIter != intVec.end() )
{
cout << *vecIter << " ";
vecIter++;
}
cout << endl;
return 0;
}
% g++ vecT.cpp
% a.out
Display using subscript notation:
7 2 8 3
Display using iterator notation:
7 2 8 3
4. Dot Product Using Iterators
% cat vecT_dot.cpp
// vector<T> example - dot product
#include <iostream>
using namespace std;
#include<cmath>
#include <vector>
double dot_product( vector<int> &, vector<int> &);
int main()
{
vector<int> A, B;
int NUM_EL, num;
double dot;
// input vector data
cout << "Enter the number of elements in the arrays:
";
cin >> NUM_EL;
cout << "Enter the elements for vector A: ";
for (int i = 0; i < NUM_EL; i++)
{
cin >> num;
A.push_back( num );
}
cout << "Enter the elements for vector B: ";
for (int i = 0; i < NUM_EL; i++)
{
cin >> num;
B.push_back( num );
}
// diplay vectors
cout << "\n\nvector A: ";
vector<int>::iterator vecIter = A.begin();
while(vecIter != A.end() )
{
cout << *vecIter << " ";
vecIter++;
}
cout << "\n\nvector B: ";
vecIter = B.begin();
while(vecIter != B.end() )
{
cout << *vecIter << " ";
vecIter++;
}
// get the dot product
dot = dot_product( A, B);
cout << "\n\ndot product = " << dot << endl;
return 0;
}
double dot_product(vector<int> &A, vector<int> &B )
{
double dot = 0.0;
vector<int>::iterator itA = A.begin();
vector<int>::iterator itB = B.begin();
while( itA != A.end() )
{
dot += (*itA) * (*itB) ;
itA++;
itB++;
}
return dot;
}
% g++ vecT_dot.cpp
% a.out
Enter the number of elements in the arrays: 5
Enter the elements for vector A: 2 2 2 2 2
Enter the elements for vector B: 1 2 3 4 5
vector A: 2 2 2 2 2
vector B: 1 2 3 4 5
dot product = 30
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