less

less

问题的起源：unordered_map<key, value> 中 key 和 map<key, value> 的 key 都要怎么组织？

#include <iostream>
#include <vector>
#include <queue>
#include <algorithm>
#include <map>
using namespace std;

//

class Job
{
public:
    int money; // 该工作的报酬
    int hard;  // 该工作的难度
public:
    Job(int money, int hard)
    {
        this->money = money;
        this->hard = hard;
    }
};
class JobComparator
{
public:
    bool operator()(const Job &o1, const Job &o2) const
    {
        // 难度由小到大；如果报酬一样，报酬由大到小
        return o1.hard != o2.hard ? (o1.hard < o2.hard) : (o1.money > o2.money);
    }
};
void test1()
{
    Job o1(1, 1), o2(1, 2), o3(2, 1), o4(2, 2), o5(7, 2);
    vector<Job> jobs = {o1, o2, o3, o4, o5};
    cout << "sorted by JobComparator()" << endl;
    stable_sort(jobs.begin(), jobs.end(), JobComparator());
    for (auto &it : jobs)
    {
        cout << it.hard << " " << it.money << endl;
    }

    cout << "sorted by lambda" << endl;
    auto cmp = [](const Job &o1, const Job &o2) -> bool
    {
        // 难度由小到大；如果报酬一样，报酬由大到小
        return o1.hard != o2.hard ? (o1.hard < o2.hard) : (o1.money > o2.money);
    };
    stable_sort(jobs.begin(), jobs.end(), cmp);
    for (auto &it : jobs)
    {
        cout << it.hard << " " << it.money << endl;
    }

    cout << "priority_queue<Job, vector<Job>, JobComparator>" << endl;
    priority_queue<Job, vector<Job>, JobComparator> pq(jobs.begin(), jobs.end());
    while (!pq.empty())
    {
        Job cur = pq.top();
        pq.pop();
        cout << cur.hard << " " << cur.money << endl;
    }
}

void test2()
{
    int x = 1;
    int y = 2;
    auto plus = [=](int a, int b) mutable -> int
    {
        x++;
        return x + y + a + b;
    };
    int c = plus(1, 2);
    cout << c << " " << x << endl;
}

int main()
{
    test1();
    // test2();
    return 0;
}