vector<pair<vector<int>, int>>

您好！您提到了一个类型为 `vector<pair<vector<int>, int>>` 的变量。这是一个向量，每个元素都是一个 `pair`，包含一个整数向量和一个整数值。

这样的数据结构可以用来存储多个整数向量及其对应的整数值。每个 `pair` 中的第一个元素是一个整数向量，第二个元素是一个整数值。

您可以使用该数据结构来表示多个向量与其对应的标签或其他相关信息。例如，您可以将一组向量与它们的分类标签结合起来存储。

希望这可以回答您的问题！如果您有任何其他问题，请随时提问。

相关问题

vector<vector<pair<int,int>>>

This is a vector of vectors, where each element of the outer vector is a vector of pairs of integers.

For example,

vector<vector<pair<int,int>>> v;

creates an empty vector of vectors. To add a vector of pairs to this, we can do:

vector<pair<int,int>> inner; // create an inner vector
inner.push_back(make_pair(1,2)); // add a pair to the inner vector
inner.push_back(make_pair(3,4)); // add another pair to the inner vector
v.push_back(inner); // add the inner vector to the outer vector

Now, `v` contains one vector of pairs:

v = [
    [(1,2), (3,4)]
]

We can add more vectors of pairs to `v` in a similar way.

This data structure is useful for storing a collection of pairs where each pair belongs to a different group or category. For example, if we are storing the grades of students in a class, we can have a vector for each subject and each vector contains pairs of (student_id, grade).

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.