uva 535

卡經度一堆問題

double spherical_distance(double lat1,double lon1,double lat2,double lon2) {

double dlon = lon2 - lon1;
double dlat = lat2 - lat1;
double a = pow((sin(dlat/2)),2) + cos(lat1) * cos(lat2) * pow(sin(dlon/2), 2);
double c = 2 * atan2(sqrt(a), sqrt(1-a));
double d = r * c;

return d;
}

 

上面這個算法可以改善精度問題

 

//====================================================================||
//                                                                    ||
//                                                                    ||
//                         Author : GCA                               ||
//                  6AE7EE02212D47DAD26C32C0FE829006                  ||
//====================================================================||
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <string>
#include <cmath>
#include <climits>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <cctype>
#include <utility>
using namespace std;
#ifdef ONLINE_JUDGE
#define ll "%lld"
#else
#define ll "%I64d"
#endif
typedef unsigned int uint;
typedef long long int Int;
#define Set(a,s) memset(a,s,sizeof(a))
#define Write(w) freopen(w,"w",stdout)
#define Read(r) freopen(r,"r",stdin)
#define Pln() printf("\n")
#define I_de(x,n)for(int i=0;i<n;i++)printf("%d ",x[i]);Pln()
#define De(x)printf(#x"%d\n",x)
#define For(i,x)for(int i=0;i<x;i++)
#define CON(x,y) x##y
#define Pmz(dp,nx,ny)for(int hty=0;hty<ny;hty++){for(int htx=0;htx<nx;htx++){\
    printf("%d ",dp[htx][hty]);}Pln();}
#define M 55
#define PII pair<int,int>
#define PB push_back
#define oo INT_MAX
#define Set_oo 0x3f
#define Is_debug true
#define debug(...) if(Is_debug)printf("DEBUG: "),printf(__VA_ARGS__)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin();it!=(c).end();it++)
#define eps 1e-6
bool xdy(double x,double y){return x>y+eps;}
bool xddy(double x,double y){return x>y-eps;}
bool xcy(double x,double y){return x<y-eps;}
bool xcdy(double x,double y){return x<y+eps;}
int min3(int x,int y,int z){
    int tmp=min(x,y);
    return min(tmp,z);
}
int max3(int x,int y,int z){
    int tmp=max(x,y);
    return max(tmp,z);
}
double r=6378;
double pi=3.141592653589793;
map<string,pair<double,double> > sid;
double cal(string a,string b){
    double alat=sid[a].first;
    double alon=sid[a].second;
    double blat=sid[b].first;
    double blon=sid[b].second;
    double dlon=blon-alon;
    double dlat=blat-alat;
    double ans=pow(sin(dlat/2),2)+cos(alat)*cos(blat)*pow(sin(dlon/2),2);
    double cc=2*atan2(sqrt(ans),sqrt(1-ans));
    return r*cc;
    //return r*acos(sin(alat)*sin(blat)+cos(alat)*cos(blat)*cos(blon-alon));
}
int main() {
    ios_base::sync_with_stdio(0);

        char str[1000],str2[1000];
        double x,y;
        for(;scanf("%s",str);){
            if(!strcmp(str,"#"))break;
            scanf("%lf%lf",&x,&y);
//            if(x<0)x+=90;
//            if(y<0)y+=180;
            sid[str].first=x*pi/180;
            sid[str].second=y*pi/180;
        }
        for(;scanf("%s %s",str,str2)==2;){
            if(!strcmp(str,"#"))break;
            if(!sid.count(str)||!sid.count(str2)){
                printf("%s - %s\nUnknown\n",str,str2);
            }else
                printf("%s - %s\n%.0f km\n",str,str2,cal(str,str2));
        }


















}