vector1.cpp

来自「C#一个实例源代码」· C++ 代码 · 共 62 行

/* The following code example is taken from the book
 * "The C++ Standard Library - A Tutorial and Reference"
 * by Nicolai M. Josuttis, Addison-Wesley, 1999
 *
 * (C) Copyright Nicolai M. Josuttis 1999.
 * Permission to copy, use, modify, sell and distribute this software
 * is granted provided this copyright notice appears in all copies.
 * This software is provided "as is" without express or implied
 * warranty, and with no claim as to its suitability for any purpose.
 */
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;

int main()
{
    // create empty vector for strings
    vector<string> sentence;

    // reserve memory for five elements to avoid reallocation
    sentence.reserve(5);

    // append some elements
    sentence.push_back("Hello,");
    sentence.push_back("how");
    sentence.push_back("are");
    sentence.push_back("you");
    sentence.push_back("?");

    // print elements separated with spaces
    copy (sentence.begin(), sentence.end(),
          ostream_iterator<string>(cout," "));
    cout << endl;

    // print ``technical data''
    cout << "  max_size(): " << sentence.max_size() << endl;
    cout << "  size():     " << sentence.size()     << endl;
    cout << "  capacity(): " << sentence.capacity() << endl;

    // swap second and fourth element
    swap (sentence[1], sentence[3]);

    // insert element "always" before element "?"
    sentence.insert (find(sentence.begin(),sentence.end(),"?"),
                     "always");

    // assign "!" to the last element
    sentence.back() = "!";
    
    // print elements separated with spaces
    copy (sentence.begin(), sentence.end(),
          ostream_iterator<string>(cout," "));
    cout << endl;

    // print ``technical data'' again
    cout << "  max_size(): " << sentence.max_size() << endl;
    cout << "  size():     " << sentence.size()     << endl;
    cout << "  capacity(): " << sentence.capacity() << endl;
}