set练习

#include <iostream>
#include <set>
#include <vector>

using namespace std;

int main()
{
    set<int> setInt;
    vector<int> ivec;
    for(vector<int>::size_type i = 0; i != 11; ++i)
        ivec.push_back(i);
    setInt.insert(ivec.begin(), ivec.end());
    setInt.insert(11);
    set<int>::iterator itor1 = setInt.find(9);//  这个也对，为什么const类型的键值可以用非const的迭代器？？？？？
    set<int>::const_iterator itor2 = setInt.find(10);
    if(itor1 != setInt.end())
        cout << *itor1 << endl;
  /*
    *itor1 = 12;    //error：keys in a set are read-only 正如不能修改mao中元素的键部分一样，set中的键也是const，在获取迭代器后只能对其进行读操作
  */
    if(itor2 != setInt.end())
        cout << *itor2 << endl;
    system("pause");
    return 0;
}

　　

#include <iostream>
#include <string>
#include <utility>
#include <vector>
#include <set>
#include <map>

using namespace std;

void restricted_wc( vector<string> strVec, map<string, int> &wordCount )
{
    // create a set of excluded words
    set<string> excluded;
    for ( vector<string>::iterator it = strVec.begin(); it != strVec.end(); ++it )
    {
        excluded.insert( *it );
    }

    string word;
    cout << " Input some words to count the words in wordCount(map) ( ctrl + z to end): "
         << endl;
    cin.clear();
    while ( cin >> word )
    {
        if ( !excluded.count( word ) )
            ++wordCount[ word ];
    }
}

int main(int argc, char* argv[])
{
    cout << " Input some words to vector<string> excluded ( ctrl + z to end): " << endl;
    vector<string> excludedVec;
    string excludedWord;
    while ( cin >> excludedWord )
        excludedVec.push_back( excludedWord );

   // use restricted_wc()
    map< string, int > wordCount;
    restricted_wc( excludedVec, wordCount );

    // show out the map:wordCount
    cout << "
	Show out the map:wordCount: " << endl;
    for ( map< string, int >::iterator it = wordCount.begin(); it != wordCount.end(); ++it )
    {
        cout << " The word '" << (*it).first << "' appears for " << (*it).second << " times. " << endl;
    }

    system("pause");
    return 0;
}