HDU 5033 Building

  1 #include<cstdio>
  2 #include<iostream>
  3 #include<algorithm>
  4 #include<cstring>
  5 #include<cmath> 
  6 using namespace std;
  7 const int maxn = 100005;
  8 const double PI = acos(-1.0);
  9 struct node
 10 {
 11     double x,h;
 12 }building[maxn];
 13 struct Node
 14 {
 15     double x,left,right;
 16     int ci;
 17 }men[maxn];
 18 bool cmpb(node a,node b)
 19 {
 20     if(a.h != b.h)
 21     return a.h > b.h; 
 22     else return a.x  < b.x;
 23 }
 24 bool cmpm(Node a,Node b)
 25 {
 26     return a.x < b.x;
 27 }
 28 bool cmpci(Node a,Node b)
 29 {
 30     return a.ci < b.ci;
 31 }
 32 int find(double x,int l,int r)
 33 {
 34     while(l < r)
 35     {
 36         int mid = (l + r) >> 1;
 37         if(men[mid].x >= x)
 38         r = mid;
 39         else l = mid + 1;
 40     }
 41     return l;
 42 }
 43 
 44 double zhuanhua(double a,double b)
 45 {
 46     double temp = PI - (atan(a) + atan(b));
 47     temp = 180.0 * temp / PI;
 48     return temp;
 49 }
 50 int main()
 51 {
 52     int T,kase = 1,n,q;
 53     scanf("%d",&T);
 54     while(T--)
 55     {
 56         scanf("%d",&n);
 57         for(int i = 1;i <= n;++i)
 58         scanf("%lf%lf",&building[i].x,&building[i].h);    
 59         scanf("%d",&q);
 60         for(int i  = 1;i <= q;++i)
 61         {
 62             scanf("%lf",&men[i].x);
 63             men[i].ci = i;
 64             men[i].left = men[i].right = 0;
 65         }
 66         sort(building+1,building+n+1,cmpb);
 67         sort(men+1,men+q+1,cmpm);
 68         for(int i = 1;i <= n;++i)
 69         {
 70             int m = find(building[i].x,1,q+1);    //第 m 个是第一个大于这个 x 的位置
 71     //        printf("m = %d\n",m);
 72             //////现在先往右扫
 73             int r = m;
 74             while(r <= q)
 75             {  
 76                 double k = building[i].h / (men[r].x - building[i].x);
 77                 if(k > men[r].right) 
 78                 men[r++].right = k;
 79                 else break;
 80             }
 81             int l = m - 1;
 82             while(l >= 1)
 83             {
 84                 double k = building[i].h / (building[i].x - men[l].x);
 85                 if(k > men[l].left)
 86                 men[l--].left = k;
 87                 else break;
 88             }
 89         }
 90         sort(men+1,men+q+1,cmpci);
 91         printf("Case #%d:\n",kase++);
 92         for(int i = 1;i <= q;++i)
 93             printf("%.10lf\n",zhuanhua(men[i].left,men[i].right));
 94     }
 95     return 0;
 96 }
 97 /*
 98 33
 99 5
100 1 2
101 3 3
102 5 1
103 7 4
104 9 2
105 4
106 2
107 4
108 6
109 8
110 */