155. 内存分配

https://www.acwing.com/problem/content/157/

#include <iostream>
#include <algorithm>
#include <queue>
#include <set>
#include <vector>

using namespace std;

typedef pair<int, int> PII;
int n;

queue<PII> q;    // <len，duration>
set<PII> memory; // <start, len>
priority_queue<PII, vector<PII>, greater<PII>> heap; // <release time, start>
int now, cnt;

void init(int n) {
    memory.insert({-1, 1});
    memory.insert({n, 1});
}

bool allocate(int t, int m, int p)
{
    for (auto it = memory.begin(); it != memory.end(); it ++ )
    {
        auto jt = it;
        jt ++ ;
        if (jt != memory.end())
        {
            int start = it->first + it->second;
            if (m <= jt->first - 1 - start + 1)
            {
                memory.insert({start, m});
                heap.push({t + p, start});
                return true;
            }
        }
    }

    return false;
}

void release(int t)
{
    while (heap.size() && heap.top().first <= t)
    {
        int cur = heap.top().first;
        while (heap.size() && heap.top().first == cur)
        {
            auto top = heap.top();
            heap.pop();
            auto it = memory.lower_bound({top.second, 0});
            memory.erase(it);
        }

        now = cur;
        while (q.size())
        {
            auto front = q.front();
            if (allocate(cur, front.first, front.second))
            {
                q.pop();
            }
            else break;
        }
    }
}

int main()
{
    cin >> n;
    int t, m, p;

    init(n);
    while (cin >> t >> m >> p, t || m || p)
    {
        release(t);
        if (!allocate(t, m, p))
        {
            q.push({m, p});
            cnt ++ ;
        }
    }

    release(2e9);

    cout << now << endl << cnt << endl;

    return 0;
}