sort

sort(a, a + 5);		//sort默认 升序

sort(a, a + 5, greater<int>());		// 降序

优先队列

• tips：priority_queue只需要 queue 这个头文件

#include <queue>

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

priority_queue<int, vector<int>, less<int>> pq;		// 降序

#include <iostream>
#include <queue>
using namespace std;

int a[] = {7, 10, 9, 11, 2};

int main() {
    priority_queue<int, vector<int>, less<int>> pq;
    pq.push(3);
    pq.push(1);
    pq.push(2);
    for (int i = 0; i < 3; ++ i) {
        cout << pq.top() << endl;
        pq.pop();
    }
}