• STL的堆操作 [转]


    STL里面的堆操作一般用到的只有4个:make_heap();、pop_heap();、push_heap();、sort_heap();

    他们的头文件函数是#include <algorithm>

    首先是make_heap();

    他的函数原型是:void make_heap(first_pointer,end_pointer,compare_function);

    一个参数是数组或向量的头指针,第二个向量是尾指针。第三个参数是比较函数的名字。在缺省的时候,默认是大跟堆。(下面的参数都一样就不解释了)

    作用:把这一段的数组或向量做成一个堆的结构。范围是[first,last)

    然后是pop_heap();

    它的函数原型是:void pop_heap(first_pointer,end_pointer,compare_function);

    作用:pop_heap()不是真的把最大(最小)的元素从堆中弹出来。而是重新排序堆。它
    把first和last交换,然后将[first,last-1)的数据再做成一个堆。

    接着是push_heap() void pushheap(first_pointer,end_pointer,compare_function);

    作用:push_heap()假设由[first,last-1)是一个有效的堆,然后,再把堆中的新元素加
    进来,做成一个堆。

    最后是sort_heap()void sort_heap(first_pointer,end_pointer,compare_function);

    作用是sort_heap对[first,last)中的序列进行排序。它假设这个序列是有效堆。(当然
    ,经过排序之后就不是一个有效堆了)

      

      
    下面是例程:

    #include<algorithm>

    #include<cstdio>

    using namespace std;

    bool cmp(int a,int b)

    {
    return a>b;
    }
    int main()
    {
    int i,number[20]={29,23,20,22,17,15,26,51,19,12,35,40};

    make_heap(&number[0],&number[12]);

    //结果是:51 35 40 23 29 20 26 22 19 12 17 15

    for(i=0;i<12;i++)

    printf("%d ",number[i]);

    printf("\n");

    make_heap(&number[0],&number[12],cmp);

    //结果:12 17 15 19 23 20 26 51 22 29 35 40

    for(i=0;i<12;i++)

    printf("%d ",number[i]);

    printf("\n");

    //加入元素8

    number[12]=8;

    //加入后调整

    push_heap(&number[0],&number[13],cmp);

    //结果:8 17 12 19 23 15 26 51 22 35 40 20

    for(i=0;i<13;i++)

    printf("%d ",number[i]);

    printf("\n");

    //弹出元素8

    pop_heap(&number[0],&number[13],cmp);

    //结果:12 17 15 19 23 20 26 51 22 29 35 40

    for(i=0;i<13;i++)

    printf("%d ",number[i]);

    printf("\n");

    sort_heap(&number[0],&number[12],cmp);

    //结果不用说都知道是有序的了!

    for(i=0;i<12;i++)

    printf("%d ",number[i]);

    return 0;

    }
    Compile options needed: /GX
    //
    // heap_functions.cpp : Illustrates how to use the
    // make_heap, sort_heap, push_heap
    // and pop_heap functions.
    //
    // Functions:
    //
    // make_heap : convert a sequence to a heap
    // sort_heap : sort a heap
    // push_heap : insert an element in a heap
    // pop_heap : remove the top element from a heap
    //
    // Written by Kalindi Sanghrajka
    // of Microsoft Product Support Services,
    // Software Core Developer Support.
    // Copyright (c) 1996 Microsoft Corporation. All rights reserved.
    //////////////////////////////////////////////////////////////////////

    // 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;
    void main()
    {
    const int VECTOR_SIZE = 8 ;

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

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

    IntVector Numbers(VECTOR_SIZE) ;

    IntVectorIt it ;

    // Initialize vector Numbers
    Numbers[0] = 4 ;
    Numbers[1] = 10;
    Numbers[2] = 70 ;
    Numbers[3] = 10 ;
    Numbers[4] = 30 ;
    Numbers[5] = 69 ;
    Numbers[6] = 96 ;
    Numbers[7] = 100;

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

    // convert Numbers into a heap
    make_heap(Numbers.begin(), Numbers.end()) ;

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

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

    // sort the heapified sequence Numbers
    sort_heap(Numbers.begin(), Numbers.end()) ;

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

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

    //insert an element in the heap
    Numbers.push_back(7) ;
    push_heap(Numbers.begin(), Numbers.end()) ;

    // you need to call make_heap to re-assert the
    // heap property
    make_heap(Numbers.begin(), Numbers.end()) ;

    cout << "After calling push_heap and make_heap\n" << endl ;

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

    // remove the root element from the heap Numbers
    pop_heap(Numbers.begin(), Numbers.end()) ;

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

    // print content of Numbers
    cout << "Numbers { " ;
    for(it = Numbers.begin(); it != Numbers.end(); it++)
    cout << *it << " " ;
    cout << " }\n" << endl ;
    }
    程序输出为:

    Numbers { 4 10 70 10 30 69 96 100 }

    之后调用 make_heap

    Numbers { 100 30 96 10 4 69 70 10 }

    之后调用 sort_heap

    Numbers { 4 10 10 30 69 70 96 100 }

    之后调用 push_heap 和 make_heap

    Numbers { 100 69 96 30 4 70 10 10 7 }

    之后调用 pop_heap

    Numbers { 96 69 70 30 4 7 10 10 100 }


    [转] : http://apps.hi.baidu.com/share/detail/15747259
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  • 原文地址:https://www.cnblogs.com/longdouhzt/p/2256000.html
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