C++ priority_queue and comparator

std::greater or less

priority_queue<int,vector<int>,greater<int>> pq;

use function

bool compare(ListNode* a, ListNode* b)
{
   return (a->val > b->val);
}

priority_queue<ListNode*, vector<ListNode*>, decltype(&compare)> q(compare);

using lambda to compare

    auto compare = [](int lhs, int rhs)
                {
                    return lhs < rhs;
                };

    std::priority_queue<int, std::vector<int>, decltype(compare)> q(compare);

struct

struct Compare
{
    bool operator()(const int& lhs, const int& rhs)
    {
        return lhs < rhs;
    }
};
priority_queue<int,vector<int>, Compare > pq;