prog20_02.cpp

一本语言类编程书籍

// Program 20.2 Manipulations of the vector<> container  File prog20_02.cpp
#include <iostream>
#include <vector>                                // For the vector container
#include <algorithm>                             // For the copy() function
using std::cout;
using std::endl;
using std::vector;

// Display a sequence of elements
void show_sequence(vector<int>::const_iterator first, vector<int>::const_iterator last) {
  cout << "{ ";
  std::copy(first, last, std::ostream_iterator<int>(cout, " "));
  cout << "}" << endl;
}

// Display the contents of a vector
void inspect_vector(const vector<int>& v) {
  cout << "  vector has " << v.size() << " elements: ";
  show_sequence(v.begin(), v.end());
}

int main() {
  vector<int> v;                                // Create empty vector
  cout << "new vector created" << endl;
  inspect_vector(v);

  cout << "filling vector from array" << endl;
  int values[] = {1, 3, 7, 5};
  v.insert(v.end(), values+1, values+3);        // Insert two elements
  inspect_vector(v);

  cout << "appending value 5" << endl;
  v.push_back(5);                               // Add an element at the end
  inspect_vector(v);

  cout << "erasing element at offset 1" << endl;
  v.erase(&v[1]);                               // Remove the second element
  inspect_vector(v);

  cout << "inserting element 4 at offset 1" << endl;
  v.insert (v.begin()+1, 4);                    // Insert an element
  inspect_vector(v);

  cout << "clearing all elements" << endl;
  v.clear();                                    // Delete all elements
  inspect_vector(v);

  return 0;
}