HDU - 4995 - Revenge of kNN

  1 #include <iostream>
  2 #include <cstring>
  3 #include <queue>
  4 #include <algorithm>
  5 #include <cstdio>
  6 using namespace std;
  7 int m,n,k;
  8 struct node
  9 {
 10     double point;
 11     double val;
 12     int id;
 13 };
 14 bool comp(const node &a,const node& b)
 15 {
 16     return a.point<b.point;
 17 }
 18 int hashs[110000+10];
 19 node nodes[110000+10];
 20 void init()
 21 {
 22     cin>>n>>m>>k;
 23     for(int i=0;i<n;i++)
 24     {
 25         double a;
 26         double b;
 27         scanf("%lf%lf",&a,&b);
 28         nodes[i].point=a;
 29         nodes[i].val=b;
 30         nodes[i].id = i;
 31     }
 32     sort(nodes,nodes+n,comp);
 33     for(int i=0;i<n;i++)
 34     {
 35         hashs[nodes[i].id+1]=i;
 36     }
 37 }
 38 double solve()
 39 {
 40     double SUM=0;
 41     for(int i=0;i<m;i++)
 42     {
 43         int t;
 44         scanf("%d",&t);
 45      //   cout<<t<<endl;
 46         int mid=hashs[t];
 47         int l=mid-1,r=mid+1;
 48         int K=k;
 49         double sum=0;
 50         while(K--)
 51         {
 52             if(l>=0&&r<n)
 53             {
 54                 double d1=nodes[l].point;
 55                 double d2=nodes[r].point;
 56                 double t1=nodes[mid].point-d1;
 57                 double t2=d2-nodes[mid].point;
 58                // cout<<t1<<" "<<t2<<" "<<"*"<<endl;
 59                 if(t1<t2)
 60                 {
 61                     sum+=nodes[l].val;
 62                    // cout<<nodes[l].val<<" "<<l<<endl;
 63                     l--;
 64                 }
 65                 else if(t1>t2)
 66                 {
 67                     sum+=nodes[r].val;
 68                //     cout<<nodes[r].val<<" "<<r<<endl;
 69                     r++;
 70                 }else if(t1==t2)
 71                 {
 72                     if(nodes[l].id<nodes[r].id)
 73                     {
 74                         sum+=nodes[l].val;
 75                         l--;
 76                     }
 77                     else
 78                     {
 79                         sum+=nodes[r].val;
 80                         r++;
 81                     }
 82                 }
 83             }
 84             else if(l>=0)
 85             {
 86                 sum+=nodes[l].val;
 87               //  cout<<nodes[l].val<<" "<<l<<endl;
 88                 l--;
 89             }else if(r<n)
 90             {
 91                 sum+=nodes[r].val;
 92              //   cout<<nodes[r].val<<" "<<r<<endl;
 93                 r++;
 94             }
 95         }
 96       //  cout<<sum<<" *"<<endl;
 97         sum=sum/k;
 98         //cout<<sum<<endl;
 99         SUM+=sum;
100         nodes[mid].val=sum;
101     }
102     return SUM;
103 }
104 int main()
105 {
106     int T;
107     cin>>T;
108     while(T--)
109     {
110        init();
111        double sum=solve();
112        printf("%.6lf\n",sum);
113     }
114     return 0;
115 }