hdu 6136 Death Podracing(模拟)

 1 #include<bits/stdc++.h>
 2 #define F(i,a,b) for(int i=(a);i<=(b);++i)
 3 using namespace std;
 4 typedef pair<int,int>P;
 5 
 6 const int N=1e5+7;
 7 int t,n,L,head,vis[N],rev[N],TIM;
 8 
 9 struct VAL
10 {
11     int a,b,x,y;double val;
12     VAL(){}
13     VAL(int _a,int _b,int _x,int _y):a(_a),b(_b),x(_x),y(_y){val=1.0*_a/_b;}
14     bool operator <(const VAL&B)const{return val>B.val;}
15 };
16 struct LIST{int idx,pre,nxt;}lst[N];
17 P a[N],tmp[N];
18 priority_queue<VAL>Q;
19 
20 VAL cal(int x,int y)
21 {
22     if(a[x].first>a[y].first)swap(x,y);
23     int dis,V=abs(a[x].second-a[y].second);
24     if(a[x].second>a[y].second)
25         dis=a[y].first-a[x].first;
26     else dis=L-a[y].first+a[x].first;
27     int gcd=__gcd(dis,V);
28     dis/=gcd,V/=gcd;
29     return VAL(dis,V,x,y);
30 }
31 
32 void del(int x,int y)
33 {
34     int lx=rev[x],ly=rev[y];
35     if(lst[lx].pre==ly)
36     {
37         lst[lx].pre=lst[ly].pre;
38         lst[lst[ly].pre].nxt=lx;
39         Q.push(cal(x,lst[lst[ly].pre].idx));
40     }else
41     {
42         lst[lx].nxt=lst[ly].nxt;
43         lst[lst[ly].nxt].pre=lx;
44         Q.push(cal(x,lst[lst[ly].nxt].idx));
45     }
46 }
47 
48 int main(){
49     scanf("%d",&t);
50     while(t--)
51     {
52         TIM++,scanf("%d%d",&n,&L);
53         F(i,1,n)scanf("%d",&a[i].first);
54         F(i,1,n)scanf("%d",&a[i].second);
55         F(i,1,n)tmp[i]=P(a[i].first,i);
56         sort(tmp+1,tmp+1+n),head=1;
57         F(i,1,n)lst[i]=LIST{tmp[i].second,i-1,i+1},rev[tmp[i].second]=i;
58         lst[n].nxt=1,lst[1].pre=n;
59         while(!Q.empty())Q.pop();
60         F(i,1,n)Q.push(cal(lst[i].idx,lst[lst[i].nxt].idx));
61         VAL ans;
62         F(i,2,n)
63         {
64             VAL now=Q.top();Q.pop();
65             while(vis[now.x]==TIM||vis[now.y]==TIM)
66                 now=Q.top(),Q.pop();
67             if(i==n)ans=now;
68             int x=now.x,y=now.y;
69             if(x<y)swap(x,y);
70             del(x,y),vis[y]=TIM;
71         }
72         printf("%d/%d\n",ans.a,ans.b);
73     }
74     return 0;
75 }