Predicate Version of partial_sort_copy

在 Visual C++ 演示如何使用 partial_sort_copy 标准模板库函数的 (STL)谓词版本。

template<class InputIterator, RandomAccessIterator, class Compare> inline
   RandomAccessIterator partial_sort(
      InputIterator First1,
       InputIterator Last1,
      RandomAccessIterator First2,
      RandomAccessIterator Last2,
      Compare Compare
   )

备注

备注

类/参数名在原型不匹配版本在头文件。修改某些提高可读性。

partial_sort_copy 排序算法最小 n 元素， n = min(Last1 -First1), (Last2 -First2)，序列 [First1， Last1) 和复制到序列 [First2、 First2 +] n的结果。 partial_sort_copy 的谓词版本用于比较 compare 功能。

示例

// partial_sort_copyP.cpp
// compile with: /EHsc
// Illustrates how to use the predicate version
// of the partial_sort_copy function.
//
// Functions:
//    partial_sort_copy : Sort the smallest N elements in a sequence
//                        and copy the resulting sequence
//                        to another sequence.
//////////////////////////////////////////////////////////////////////

// disable warning C4786: symbol greater than 255 character,
// okay to ignore
#pragma warning(disable: 4786)

#include <iostream>
#include <algorithm>
#include <functional>
#include <vector>

using namespace std ;

int main()
{
    const int VECTOR_SIZE = 8 ;

    // Define a template class vector of int
    typedef vector<int> IntVector;

    //Define an iterator for template class vector of strings
    typedef IntVector::iterator IntVectorIt;

    IntVector Numbers(VECTOR_SIZE);
    IntVector Result(4);

    IntVectorIt start, end, it;

    // Initialize vector Numbers
    Numbers[0] = 4;
    Numbers[1] = 10;
    Numbers[2] = 70;
    Numbers[3] = 30;
    Numbers[4] = 10;
    Numbers[5] = 69;
    Numbers[6] = 96;
    Numbers[7] = 7;

    start = Numbers.begin();    // location of first
                                // element of Numbers

    end = Numbers.end();        // one past the location
                                // last element of Numbers

    cout << "Before calling partial_sort_copy\n" << endl;

    // print content of Numbers
    cout << "Numbers { ";
    for(it = start; it != end; it++)
        cout << *it << " ";
    cout << " }\n" << endl;

    // sort the smallest 4 elements in the Numbers
    // and copy the results in Result
    partial_sort_copy(start, end, Result.begin(),Result.end());

    cout << "After calling partial_sort_copy\n" << endl;

    cout << "Numbers { ";
    for(it = start; it != end; it++)
        cout << *it << " ";
    cout << " }\n" << endl;

    cout << "Result { " ;
    for(it = Result.begin(); it != Result.end(); it++)
        cout << *it << " ";
    cout << " }\n" << endl;
}

Output

Before calling partial_sort_copy

Numbers { 4 10 70 30 10 69 96 7  }

After calling partial_sort_copy

Numbers { 4 10 70 30 10 69 96 7  }

Result { 4 7 10 10  }

要求

**标题:**algorithm

请参见

概念

标准模板库示例