ZJNU 1422 - 碰撞的小球

 1 /*
 2 Written By StelaYuri
 3 */
 4 #pragma GCC optimize(3)
 5 #include<iostream>
 6 #include<algorithm>
 7 #include<cctype>
 8 using namespace std;
 9 int pos[1000000],dir[1000000],ans[1000000];
10 const int bsz=1<<16;
11 char bf[bsz],*head,*tail;
12 inline char gc()
13 {
14     if(head==tail)
15     {
16         int l=fread(bf,1,bsz,stdin);
17         tail=(head=bf)+l;
18     }
19     return *head++;
20 }
21 inline int read()
22 {
23     int x=0,f=1;char c=gc();
24     for(;!isdigit(c);c=gc())
25         if(c==‘-‘)
26             f=-1;
27     for(;isdigit(c);c=gc())
28         x=x*10+c-‘0‘;
29     return x*f;
30 }
31 inline void write(int x)
32 {
33     if(x>=10)
34         write(x/10);
35     putchar(x%10+‘0‘);
36 }
37 int main()
38 {
39     ios::sync_with_stdio(0);
40     cin.tie(0);cout.tie(0);
41     int i,vd,nl,n,m,L;
42     cin>>n>>m>>L;
43     if(n>30000)
44     {
45         for(i=0;i<n;i++)
46             pos[i]=read();
47         for(i=0;i<n;i++)
48             dir[i]=read();
49         for(i=0;i<n;i++)
50         {
51             vd=read();
52             if(dir[i])
53                 nl=L+1-pos[i];
54             else 
55                 nl=pos[i];
56             ans[i]=nl/vd+(nl%vd?1:0);
57         }
58         sort(ans,ans+n);
59         write(ans[n-m-1]);
60     }
61     else
62     {
63         for(i=0;i<n;i++)
64             cin>>pos[i];
65         for(i=0;i<n;i++)
66             cin>>dir[i];
67         for(i=0;i<n;i++)
68         {
69             cin>>vd;
70             if(dir[i])
71                 nl=L+1-pos[i];
72             else 
73                 nl=pos[i];
74             ans[i]=nl/vd+(nl%vd?1:0);
75         }
76         sort(ans,ans+n);
77         cout<<ans[n-m-1];
78     }
79     
80     return 0;
81 }