C++ Primer 学习中。。

。

简单记录下我的学习过程 (代码为主)

全部容器适用(O(log(n)))     已序区间查找算法

binary_search             //二分查找。返回bool值，

includes                    //包括查找，返回bool值。

#include<iostream>

#include<cstdio>

#include<cstring>

#include<vector>

#include<algorithm>

using namespace std;

/*****************************************

//全部容器适用(O(log(n)))

已序区间查找算法

binary_search()             //二分查找。返回bool值，

includes()                  //包括查找，返回bool值。

*****************************************/

/*************************************************************************************

std::binary_search              全部排序容器适用                           algorithm

--------------------------------------------------------------------------------------

template <class ForwardIterator, class T>

  bool binary_search ( ForwardIterator first, ForwardIterator last,

                       const T& value );

template <class ForwardIterator, class T, class Compare>

  bool binary_search ( ForwardIterator first, ForwardIterator last,

                       const T& value, Compare comp );

//eg：

template <class ForwardIterator, class T>

    bool binary_search ( ForwardIterator first, ForwardIterator last, const T& value )

    {

        first = lower_bound(first,last,value);

        return (first!=last && !(value<*first));

    }

*************************************************************************************/

/*************************************************************************************

std::includes                   全部排序容器适用                           algorithm

--------------------------------------------------------------------------------------

template <class InputIterator1, class InputIterator2>

  bool includes ( InputIterator1 first1, InputIterator1 last1,

                  InputIterator2 first2, InputIterator2 last2 );

template <class InputIterator1, class InputIterator2, class Compare>

  bool includes ( InputIterator1 first1, InputIterator1 last1,

                  InputIterator2 first2, InputIterator2 last2, Compare comp );

//eg：

template <class InputIterator1, class InputIterator2>

    bool includes ( InputIterator1 first1, InputIterator1 last1,

                  InputIterator2 first2, InputIterator2 last2 )

    {

        while (first1!=last1)

        {

            if (*first2<*first1) break;

            else if (*first1<*first2) ++first1;

            else { ++first1; ++first2; }

            if (first2==last2) return true;

        }

        return false;

    }

*************************************************************************************/

bool myfunction (int i,int j)  { return (i<j);}

int main()

{

    int myints[] = {1,2,3,4,5,4,3,2,1};

    vector<int> v(myints,myints+9);                         // 1 2 3 4 5 4 3 2 1

    // using default comparison:

    sort (v.begin(), v.end());

    cout << "looking for a 3...  ";

    if (binary_search (v.begin(), v.end(), 3))

    cout << "found!\n"; else cout << "not found.\n";

    // using myfunction as comp:

    sort (v.begin(), v.end(), myfunction);

    cout << "looking for a 6... ";

    if (binary_search (v.begin(), v.end(), 6, myfunction))

        cout << "found!\n"; else cout << "not found.\n";

    cout<<endl;

/**----------------------------------------------------------------------------------**/

    int container[] = {5,15,10,25,20,35,30,50,45,40};

    int continent[] = {40,30,20,10};

    sort (container,container+10);

    sort (continent,continent+4);

    // using default comparison:

    if ( includes(container,container+10,continent,continent+4) )

        cout << "container includes continent!" << endl;

    // using myfunction as comp:

    if ( includes(container,container+10,continent,continent+4, myfunction) )

        cout << "container includes continent!" << endl;

	return 0;

}

/*****

Output

    looking for a 3...  found!

    looking for a 6... not found.

    container includes continent!

    container includes continent!

*/