自定义结构体比较大小

#include <iostream>
#include <stdio.h>
#include <cstring>
#include <algorithm>
#include <cstring>
#include <string>
#include <vector>
#include <set>
#include <queue>
#include <stack>
#include <cmath>
#include <cctype>
#include <sstream>
using namespace std;
typedef long long ll;
const int maxn = 123456;
const int inf = 0x3f3f3f3f;
struct student
{
	int x;
	int y;
	student(int x = 0, int y = 0) :x(x), y(y) {}
};
bool operator < (const student&A, const student&B)
{
	return A.x < B.x;
}
ostream& operator <<(ostream&out, const student& ST)
{
	out << "(" << ST.x << "," << ST.y << ")";
	return out;
}
vector<student>v;
int main()
{
	int n = 5;
	for (int i = 0; i < n; i++)
	{
		int x, y;
		cin >> x >> y;
		student ST;
		ST.x = x;
		ST.y = y;
		v.push_back(ST);
	}
	sort(v.begin(), v.end());
	for (int i = 0; i < n; i++)
	{
		cout << v[i] << endl;
	}
	return 0;
}

自己定义了结构体比较大小的方法。。之后sort啊，优先队列啊啥的就能自己写了。。。