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C++之STL迭代器(iterator)

複製程式碼
1、vector
#include <iostream>
#include <vector>

int main()
{
    std::vector<char> charVector;

    int x;
    for (x=0; x<10; ++x)
        charVector.push_back(65 + x);

    int size = charVector.size();
    for (x=0; x<size; ++x)
    {
        std::vector<char>::iterator start =
            charVector.begin();
        charVector.erase(start);
        std::vector<char>::iterator iter;
        for (iter = charVector.begin(); 
                iter != charVector.end(); iter++)
        {
            std::cout << *iter;
        }
        std::cout << std::endl;
    }

    return 0;
}
2、deque
#include <iostream>
#include <deque>

int main()
{
    std::deque<char> charDeque;
    int x;
    for (x=0; x<10; ++x)
        charDeque.push_front(65 + x);

    int size = charDeque.size();
    for (x=0; x<size; ++x)
    {
        std::deque<char>::iterator start =
            charDeque.begin();
        charDeque.erase(start);
        std::deque<char>::iterator iter;
        for (iter = charDeque.begin(); 
                iter != charDeque.end(); iter++)
        {
            std::cout << *iter;
        }
        std::cout << std::endl;
    }

    return 0;
}
3、list
#include <iostream>
#include <list>

int main()
{
    // Create and populate the list.
    int x;
    std::list<char> charList;
    for (x=0; x<10; ++x)
        charList.push_front(65 + x);

    // Display contents of list.
    std::cout << "Original list: ";
    std::list<char>::iterator iter;
    for (iter = charList.begin(); 
            iter != charList.end(); iter++)
    {
        std::cout << *iter;
        //char ch = *iter;
        //std::cout << ch;
    }
    std::cout << std::endl;
    
    // Insert five Xs into the list.
    std::list<char>::iterator start = charList.begin();
    charList.insert(++start, 5, 'X');

    // Display the result.
    std::cout << "Resultant list: ";
    for (iter = charList.begin(); 
    iter != charList.end(); iter++)
    {
        std::cout << *iter;
        //char ch = *iter;
        //std::cout << ch;
    }
    
    return 0;
}
4、set
#include <iostream>
#include <set>

int main()
{
    // Create the set object.
    std::set<char> charSet;

    // Populate the set with values.
    charSet.insert('E');
    charSet.insert('D');
    charSet.insert('C');
    charSet.insert('B');
    charSet.insert('A');

    // Display the contents of the set.
    std::cout << "Contents of set: " << std::endl;
    std::set<char>::iterator iter;
    for (iter = charSet.begin(); iter != charSet.end(); iter++)
        std::cout << *iter << std::endl;
    std::cout << std::endl;

    // Find the D.
    iter = charSet.find('D');
    if (iter == charSet.end())
        std::cout << "Element not found.";
    else
        std::cout << "Element found: " << *iter;

    return 0;
}
5、multiset
#include <iostream>
#include <set>

int main()
{
    // Create the first set object.
    std::multiset<char> charMultiset1;

    // Populate the multiset with values.
    charMultiset1.insert('E');
    charMultiset1.insert('D');
    charMultiset1.insert('C');
    charMultiset1.insert('B');
    charMultiset1.insert('A');
    charMultiset1.insert('B');
    charMultiset1.insert('D');

    // Display the contents of the first multiset.
    std::cout << "Contents of first multiset: " << std::endl;
    std::multiset<char>::iterator iter;
    for (iter = charMultiset1.begin();
            iter != charMultiset1.end(); iter++)
        std::cout << *iter << std::endl;
    std::cout << std::endl;

    // Create the second multiset object.
    std::multiset<char> charMultiset2;

    // Populate the multiset with values.
    charMultiset2.insert('J');
    charMultiset2.insert('I');
    charMultiset2.insert('H');
    charMultiset2.insert('G');
    charMultiset2.insert('F');
    charMultiset2.insert('G');
    charMultiset2.insert('I');
    
    // Display the contents of the second multiset.
    std::cout << "Contents of second multiset: "
        << std::endl;
    for (iter = charMultiset2.begin();
    iter != charMultiset2.end(); iter++)
        std::cout << *iter << std::endl;
    std::cout << std::endl;
    
    // Compare the sets.
    if (charMultiset1 == charMultiset2)
        std::cout << "set1 == set2";
    else if (charMultiset1 < charMultiset2)
        std::cout << "set1 < set2";
    else if (charMultiset1 > charMultiset2)
        std::cout << "set1 > set2";
    
    return 0;
}
6、map
#include <iostream>
#include <map>

typedef std::map<int, char> MYMAP;

int main()
{
    // Create the first map object.
    MYMAP charMap1;

    // Populate the first map with values.
    charMap1[1] = 'A';
    charMap1[4] = 'D';
    charMap1[2] = 'B';
    charMap1[5] = 'E';
    charMap1[3] = 'C';

    // Display the contents of the first map.
    std::cout << "Contents of first map: " << std::endl;
    MYMAP::iterator iter;
    for (iter = charMap1.begin();
            iter != charMap1.end(); iter++)
    {
        std::cout << (*iter).first << " --> ";
        std::cout << (*iter).second << std::endl;
    }
    std::cout << std::endl;

    // Create the second map object.
    MYMAP charMap2;

    // Populate the first map with values.
    charMap2[1] = 'F';
    charMap2[4] = 'I';
    charMap2[2] = 'G';
    charMap2[5] = 'J';
    charMap2[3] = 'H';

    // Display the contents of the second map.
    std::cout << "Contents of second map: " << std::endl;
    for (iter = charMap2.begin();
            iter != charMap2.end(); iter++)
    {
        std::cout << (*iter).first << " --> ";
        std::cout << (*iter).second << std::endl;
    }
    std::cout << std::endl;

    // Compare the maps.
    if (charMap1 == charMap2)
        std::cout << "map1 == map2";
    else if (charMap1 < charMap2)
        std::cout << "map1 < map2";
    else if (charMap1 > charMap2)
        std::cout << "map1 > map2";
    
    return 0;
}
7、multimap
#include <iostream>
#include <map>

typedef std::multimap<int, char> MYMAP;

int main()
{
    // Create the first multimap object.
    MYMAP charMultimap;

    // Populate the multimap with values.
    charMultimap.insert(MYMAP::value_type(1,'A'));
    charMultimap.insert(MYMAP::value_type(4,'C'));
    charMultimap.insert(MYMAP::value_type(2,'B'));
    charMultimap.insert(MYMAP::value_type(7,'E'));
    charMultimap.insert(MYMAP::value_type(5,'D'));
    charMultimap.insert(MYMAP::value_type(3,'B'));
    charMultimap.insert(MYMAP::value_type(6,'D'));

    // Display the contents of the first multimap.
    std::cout << "Contents of first multimap: " << std::endl;
    MYMAP::iterator iter;
    for (iter = charMultimap.begin();
            iter != charMultimap.end(); iter++)
    {
        std::cout << (*iter).first << " --> ";
        std::cout << (*iter).second << std::endl;
    }
    std::cout << std::endl;

    // Create the second multimap object.
    MYMAP charMultimap2;

    // Populate the second multimap with values.
    charMultimap2.insert(MYMAP::value_type(1,'C'));
    charMultimap2.insert(MYMAP::value_type(4,'F'));
    charMultimap2.insert(MYMAP::value_type(2,'D'));
    charMultimap2.insert(MYMAP::value_type(7,'E'));
    charMultimap2.insert(MYMAP::value_type(5,'F'));
    charMultimap2.insert(MYMAP::value_type(3,'E'));
    charMultimap2.insert(MYMAP::value_type(6,'G'));

    // Display the contents of the second multimap.
    std::cout << "Contents of second multimap: " << std::endl;
    for (iter = charMultimap2.begin();
            iter != charMultimap2.end(); iter++)
    {
        std::cout << (*iter).first << " --> ";
        std::cout << (*iter).second << std::endl;
    }
    std::cout << std::endl;

    // Compare the multimaps.
    if (charMultimap == charMultimap2)
        std::cout << "multimap1 == multimap2";
    else if (charMultimap < charMultimap2)
        std::cout << "multimap1 < multimap2";
    else if (charMultimap > charMultimap2)
        std::cout << "multimap1 > multimap2";
    
    return 0;
}
8、stack
#include <iostream>
#include <list>
#include <stack>

int main()
{
    std::stack<int, std::list<int> > intStack;

    int x;
    std::cout << "Values pushed onto stack:"
              << std::endl;
    for (x=1; x<11; ++x)
    {
        intStack.push(x*100);
        std::cout << x*100 << std::endl;
    }

    std::cout << "Values popped from stack:"
              << std::endl;
    int size = intStack.size();
    for (x=0; x<size; ++x)
    {
        std::cout << intStack.top() << std::endl;
        intStack.pop();
    }

    return 0;
}
9、queue
#include <iostream>
#include <list>
#include <queue>

int main()
{
    std::queue<int, std::list<int> > intQueue;

    int x;
    std::cout << "Values pushed onto queue:"
              << std::endl;
    for (x=1; x<11; ++x)
    {
        intQueue.push(x*100);
        std::cout << x*100 << std::endl;
    }

    std::cout << "Values removed from queue:"
              << std::endl;
    int size = intQueue.size();
    for (x=0; x<size; ++x)
    {
        std::cout << intQueue.front() << std::endl;
        intQueue.pop();
    }

    return 0;
}
10、priority_queue
#include <iostream>
#include <list>
#include <queue>

int main()
{
    std::priority_queue<int, std::vector<int>,std::greater<int> > intPQueue;
    int x;
    intPQueue.push(400);
    intPQueue.push(100);
    intPQueue.push(500);
    intPQueue.push(300);
    intPQueue.push(200);

    std::cout << "Values removed from priority queue:"
              << std::endl;
    int size = intPQueue.size();
    for (x=0; x<size; ++x)
    {
        std::cout << intPQueue.top() << std::endl;
        intPQueue.pop();
    }

    return 0;
}