C++ vector 实例二

Posted 2022-04-30 codeworkerliming

// constructing vectors
#include <iostream>
#include <vector>

int main ()

    // constructors used in the same order as described above:
    std::vector<int> first;                                // empty vector of ints
    std::vector<int> second (4, 100);                      // four ints with value 100
    std::vector<int> third (second.begin(), second.end()); // iterating through second
    std::vector<int> fourth (third);                       // a copy of third

    std::cout << "The contents of second are:";
    for (std::vector<int>::iterator it = second.begin(); it != second.end(); ++it)
    
        std::cout << ‘ ‘ << *it;
    
    std::cout << ‘\n‘;

    // the iterator constructor can also be used to construct from arrays:
    int myints[] = 16, 2, 77, 29;
    std::vector<int> fifth (myints, myints + sizeof(myints) / sizeof(int) );

    std::cout << "The contents of fifth are:";
    for (std::vector<int>::iterator it = fifth.begin(); it != fifth.end(); ++it)
    
        std::cout << ‘ ‘ << *it;
    
    std::cout << ‘\n‘;

    return 0;