c++ - 如何遍历包含deque <MyData>元素的斐波那契堆( boost )

我正在使用斐波那契堆(boost)对元素数组进行排序，但无法遍历堆。
代码是这样的:

#include <deque>
#include <boost/heap/fibonacci_heap.hpp>
#include <iostream>

struct MyData {
     ...
     long int id;

     ...
};

struct MyCompare{
    bool operator()(const deque<MyData> &a, const deque<MyData> &b) const
    {
        return a[a.size()-1].id > b[b.size()-1].id;
    }
};


int main()
{   deque<MyData> array1;
    deque<MyData> array2;

    MyData app;
    app.id=15;
    array1.push_front(app);
    app.id=10;
    array1.push_front(app);

    app.id=5;
    array2.push_front(app);
    app.id=2;
    array2.push_front(app);

    boost::heap::fibonacci_heap<deque<MyData>, boost::heap::compare<MyCompare> > fib_heap;
    fib_heap.push(array1);
    fib_heap.push(array2);
    boost::heap::fibonacci_heap<deque<MyData>, boost::heap::compare<MyCompare> >::iterator it;
    boost::heap::fibonacci_heap<deque<MyData>, boost::heap::compare<MyCompare> >::iterator beg =fib_heap.begin();
    boost::heap::fibonacci_heap<deque<MyData>, boost::heap::compare<MyCompare> >::iterator end =fib_heap.end();

    for (it=beg;it!=end; ++it) {
        deque<MyData> elem;
        elem =*it;
        for (int k=0;k < elem.size();k++)
            cout<<" "<<elem[k].id;
        cout<<"\n";
    }


}

它在“elem = * it”行给了我这个错误:recursive_tree_iterator的实例错误:
recursive_tree_iterator(void):
Adaptor_type(0)
{}

有什么办法吗？还是使用另一个有序堆而不是斐波那契？
非常感谢你。

最佳答案

我认为错误是您不能默认构造迭代器。
尝试消除it变量的创建并将其移至for循环内:

boost::heap::fibonacci_heap<deque<MyData>, boost::heap::compare<MyCompare> >::iterator beg =fib_heap.begin();
boost::heap::fibonacci_heap<deque<MyData>, boost::heap::compare<MyCompare> >::iterator end =fib_heap.end();

for (boost::heap::fibonacci_heap<deque<MyData>, boost::heap::compare<MyCompare> >::iterator it=beg;it!=end; ++it) {
    deque<MyData> elem;
    elem =*it;
    for (size_t k=0;k < elem.size();k++)
        cout<<" "<<elem[k].id;
    cout<<"\n";
}

为了按堆顺序进行迭代，可以使用:

ordered_iterator ordered_begin(void) const;
ordered_iterator ordered_end(void) const;

另外，我认为使用auto关键字会对代码有所帮助:

for (auto it=fib_heap.begin(), end=fib_heap.end();it!=end; ++it) {
    deque<MyData> elem;
    elem =*it;
    for (size_t k=0;k < elem.size();k++)
        cout<<" "<<elem[k].id;
    cout<<"\n";
}

关于c++ - 如何遍历包含deque <MyData>元素的斐波那契堆( boost )，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/21110381/