#include <iostream>
#include <vector>
using namespace std;
void show(const char *msg, vector<int> vect);
int main() {
// Declare a vector that has an initial capacity of 10.
vector<int> v(10);
for(unsigned i=0; i < v.size(); ++i) v[i] = i*i;
show("Contents of v: ", v);
// the use of the subscripting operator.
int sum = 0;
for(unsigned i=0; i < v.size(); ++i) sum += v[i];
double avg = sum / v.size();
cout << "The average of the elements is " << avg << "\n\n";
// Add elements to the end of v.
v.push_back(100);
v.push_back(121);
show("v after pushing elements onto the end: ", v);
cout << endl;
// Now use pop_back() to remove one element.
v.pop_back();
show("v after back-popping one element: ", v);
cout << endl;
cout << "The first and last element in v as"
<< " pointed to by begin() and end()-1:\n"
<< *v.begin() << ", " << *(v.end()-1) << "\n\n";
return 0;
}
void show(const char *msg, vector<int> vect) {
cout << msg << endl;
for(unsigned i=0; i < vect.size(); ++i)
cout << vect[i] << endl;
}
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