priority_queue<int,vector<int>,greater<int> > heap;
时间: 2023-12-17 11:02:50 浏览: 28
priority_queue<int,vector<int>,greater<int> > heap; 是一个定义小根堆的优先队列,它存储整数类型的元素,并按照从小到大的顺序进行排序。这意味着在这个小根堆中,最小的元素将位于队列的顶部,而较大的元素将放置在较低的位置。你可以使用这个优先队列来实现一些需要按照特定顺序处理元素的算法。
相关问题
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq
This is a declaration of a priority queue in C++ that stores pairs of integers. The priority queue is implemented using a min-heap, which means that the smallest element will have the highest priority. The first integer in the pair is the priority and the second integer is the value.
The syntax for declaring a priority queue in C++ is:
priority_queue<data_type, container_type, comparison_function>
In this case, the data type is a pair of integers (pair<int, int>), the container type is a vector (vector<pair<int, int>>), and the comparison function is the default less-than operator (>).
However, in order to implement a min-heap, we need to use the greater-than operator (<) instead. So we pass greater<pair<int, int>> as the comparison function.
Overall, this priority queue will store pairs of integers in ascending order of their first element. If two pairs have the same first element, then they will be ordered based on their second element in ascending order as well.
priority_queue<int,vector<int>,greater<int>> q(队列从小到大排序)
是的,你说的是 STL 中的 priority_queue 容器,它可以用来实现堆(heap)数据结构。其中第二个参数是容器类型,表示底层容器采用 vector 容器,第三个参数是比较函数对象,表示元素的比较方式。当使用 greater<int> 时,元素按照从小到大的顺序排序,而使用 less<int> 时则按照从大到小的顺序排序(默认情况下,priority_queue 容器采用 less<int> 作为比较函数对象)。