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。

View Code

 1 #define REP(i, n) for (int i = 0; i < (n); i++)
 2 #define PRIQ priority_queue
 3 typedef pair<int, int> PII;
 4 typedef vector<PII> VPII;
 5 
 6 PRIQ<int, VI, less<int> > Q;
 7 VPII rec;
 8 
 9 int main() {
10 //    freopen("in", "r", stdin);
11     int T, n, q, d;
12     scanf("%d", &T);
13     while (T--) {
14         scanf("%d", &n);
15         rec.clear();
16         REP(i, n) {
17             scanf("%d%d", &q, &d);
18             rec.PB(MPR(d, q));
19         }
20         sort(ALL(rec));
21         while (!Q.empty()) Q.pop();
22         int sum = 0;
23         REP(i, n) {
24             if (sum + rec[i].SE > rec[i].FI) {
25                 if (!Q.empty()) {
26                     if (Q.top() > rec[i].SE && (sum - Q.top() + rec[i].SE <= rec[i].FI)) {
27                         sum -= Q.top();
28                         Q.pop();
29                         sum += rec[i].SE;
30                         Q.push(rec[i].SE);
31                     }
32                 }
33             } else {
34                 sum += rec[i].SE;
35                 Q.push(rec[i].SE);
36             }
37         }
38         printf("%d\n", SZ(Q));
39         if (T) puts("");
40     }
41     return 0;
42 }

——written by Lyon

posted @ 2013-03-02 01:06 LyonLys 阅读(190) 评论(0) 收藏举报

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