poj3190 Stall Reservations（贪心+STL）

Posted 2020-11-03 Surprisez

https://vjudge.net/problem/POJ-3190

cin和scanf差这么多么。。tle和300ms

思路：先对结构体x升序y升序，再对优先队列重载<，按y升序。

　　然后依次入队，如果node[i].x<=q.top().y ans++， 否则出队，入队，使用出队的那个摊位。

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<queue>
 4 #include<cstring>
 5 #include<algorithm>
 6 #include<cmath>
 7 #include<set>
 8 #define INF 0x3f3f3f3f
 9 typedef long long ll;
10 using namespace std;
11 struct Node{
12     int x, y;
13     int id;
14     bool operator<(const Node &a)const{
15         return y > a.y;
16     }
17 }node[50010];
18 int n, maxm = -INF, b[50010];
19 bool cmp(const Node a, const Node b)
20 {
21     if(a.x != b.x)
22         return a.x<b.x;
23     return a.y<b.y;
24 }
25 int main()
26 {
27     scanf("%d", &n); 
28     int ans = 1;
29     for(int i = 0; i < n; i++){
30         scanf("%d%d", &node[i].x, &node[i].y);
31         node[i].id=i+1;
32     }
33     sort(node, node+n, cmp);
34     priority_queue<Node> q;
35     q.push(node[0]);
36     b[node[0].id] = ans;
37     for(int i = 1; i < n; i++){
38         Node t = q.top();
39         if(node[i].x <= t.y){
40             q.push(node[i]);
41             ans++;
42             b[node[i].id] = ans;
43             //maxm = max(maxm, ans);
44         }
45         else if(node[i].x > t.y){
46             q.pop();
47             q.push(node[i]);
48             b[node[i].id] = b[t.id];
49             //cout << b[t.id] << "t";
50         }
51     }
52     printf("%d\n", ans);
53     for(int i = 1; i <= n; i++){
54         printf("%d\n", b[i]);
55     }
56     
57     return 0;
58 }