CodeForces 589F-Gourmet and Banquet-二分答案

 1 #include <cstdio>
 2 #include <algorithm>
 3 #include <cstring>
 4 #include <queue>
 5 
 6 using namespace std;
 7 
 8 const int maxn = 1e4+10;
 9 const int INF = 0x3f3f3f3f;
10 int N,len,a[maxn],b[maxn],save[200];;
11 
12 struct node
13 {
14     int a,b,id;
15     node(){}
16     node(int x,int y,int z):a(x),b(y),id(z){}
17     bool operator < (const node &b) const
18     {
19         return a<b.a;
20     }
21 }Dish[maxn];
22 
23 struct node2
24 {
25     int ed,id;
26     node2(int x,int y):ed(x),id(y){}
27     bool operator < (const node2 &b) const
28     {
29         return ed > b.ed;
30     }
31 };
32 
33 int solve(int ll,int rr)
34 {
35     int mid = (ll+rr)>>1,cnt=0;
36     if(ll+1 >= rr) return mid;
37     priority_queue<node2> q;
38 
39     memset(save,0,sizeof save);
40     //printf("ll:%d rr:%d\n",ll,rr);
41     for(int cur=0;cur<=len;cur++)
42     {
43         //printf("cur:%d cnt:%d num:%d\n",cur,cnt,q.size());
44         while(cnt < N && Dish[cnt].a == cur)
45         {
46              q.push(node2(Dish[cnt].b,Dish[cnt].id));
47              cnt++;
48         }
49         //printf("save:%d mid:%d\n",save[q.top().id],mid);
50         while(!q.empty() && save[q.top().id]>=mid && save[q.top().id])
51         {
52             q.pop();
53         }
54 
55         if(!q.empty())   {/*printf("id:%d++\n",q.top().id);*/save[q.top().id]++;}
56 
57         while(!q.empty() && q.top().ed <= cur+1)
58         {
59             if(save[q.top().id] < mid || save[q.top().id]==0) {/*printf("id:%d save:%d\n",q.top().id,save[q.top().id]);*/return solve(ll,mid==0?0:mid);}
60             q.pop();
61         }
62 
63         if(q.empty()&&cnt==N) return solve(mid,rr);
64     }
65 }
66 
67 int main()
68 {
69     scanf("%d",&N);
70     int l = INF,r = -INF;
71     len = -INF;
72     for(int i=0;i<N;i++)
73     {
74         scanf("%d%d",&a[i],&b[i]);
75         Dish[i] = node(a[i],b[i],i);
76         r = max(b[i]-a[i],r);
77         len = max(len,b[i]);
78     }
79     sort(Dish,Dish+N);
80     printf("%d\n",solve(0,r+1)*N);
81 }