LA 3507 Keep the Customer Satisfied (Greedy)

https://icpcarchive.ecs.baylor.edu/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=1508

　　贪心，经典题的变形，只是变成了要消耗时间，其实还是跟经典的求最大价值相似。

#define REP(i, n) for (int i = 0; i < (n); i++)
#define PRIQ priority_queue
typedef pair<int, int> PII;
typedef vector<PII> VPII;

PRIQ<int, VI, less<int> > Q;
VPII rec;

int main() {
//    freopen("in", "r", stdin);
    int T, n, q, d;
    scanf("%d", &T);
    while (T--) {
        scanf("%d", &n);
        rec.clear();
        REP(i, n) {
            scanf("%d%d", &q, &d);
            rec.PB(MPR(d, q));
        }
        sort(ALL(rec));
        while (!Q.empty()) Q.pop();
        int sum = 0;
        REP(i, n) {
            if (sum + rec[i].SE > rec[i].FI) {
                if (!Q.empty()) {
                    if (Q.top() > rec[i].SE && (sum - Q.top() + rec[i].SE <= rec[i].FI)) {
                        sum -= Q.top();
                        Q.pop();
                        sum += rec[i].SE;
                        Q.push(rec[i].SE);
                    }
                }
            } else {
                sum += rec[i].SE;
                Q.push(rec[i].SE);
            }
        }
        printf("%d\n", SZ(Q));
        if (T) puts("");
    }
    return 0;
}

——written by Lyon