В конце замечаний на русском языке исправьте "для восточной/южной" на "для восточной/западной". Спасибо (долгота)

You have to make one more "if"
######################################################################################
d = math.sin(p1) * math.sin(p2) + math.cos(p1) * math.cos(p2) * math.cos(abs(l1 - l2))
if str(d) == '-1.0000000000000002':
    d = int(d)
d = math.acos(d) * 3437.5
######################################################################################
there is a test where '-1.0000000000000002' in d so thats why acos gives error, you have to change '-1.0000000000000002' to -1

Edited by author 20.04.2023 21:49

Edited by author 20.04.2023 21:49

diameter of 6875 miles (/ 2 = 3437.5)???

the mean radius of earth is 6371.0 km (3958.8 miles)

from sys import stdin, stdout, float_info
import re
from math import sin, cos, acos, fabs

CONST_PI = acos(-1.0)
CONST_EPSILON = 2.2204460492503130808472633361816
# CONST_PI = 3.141592653589793
data = []


def solve(a, b, c, d):
    a = a + (c / 3600) + (b / 60)
    # Checking the latitude and longitude position to determine positive pr negative degree
    if d == 'SL' or d == 'WL':
        a = -a
    a = a * CONST_PI / 180
    return a


def distComp(a):
    if fabs(a) < CONST_EPSILON:
        return 0
    elif a > 0:
        return 1
    else:
        return -1


# Input
data = stdin.read().split()

# # Test Input
# data = ['Message', '#513.', 'Received', 'at', '22:30:11.', 'Current', "ship's", 'coordinates', 'are', '41^46\'00"', 'NL',
#         'and', '50^14\'00"', 'WL.', 'An', 'iceberg', 'was', 'noticed', 'at', '41^14\'11"', 'NL', 'and', '51^09\'00"', 'WL.', '===']

# data = ['Message', '#513.', 'Received', 'at', '22:30:11.', 'Current', "ship's", 'coordinates', 'are', '36^46\'00"', 'EL',
#         'and', '50^14\'00"', 'WL.', 'An', 'iceberg', 'was', 'noticed', 'at', '41^14\'11"', 'NL', 'and', '76^09\'00"', 'WL.', '===']


# Message Received
# messageReceived = [int(s) for s in re.findall(r'\b\d+\b', data[4])]
# hh = messageReceived[0]
# mm = messageReceived[1]
# ss = messageReceived[2]
# print('\nMessage Received at: ', hh, mm, ss)

# Ship's Latitude
shipLatitude = [float(s) for s in re.findall(r'\b\d+\b', data[9])]
x1 = shipLatitude[0]
x2 = shipLatitude[1]
x3 = shipLatitude[2]
x4 = data[10]
# print('\nShip Latitude: ', x1, x2, x3, x4)


# Ship's Longitude
shipLongitude = [float(s) for s in re.findall(r'\b\d+\b', data[12])]
y1 = shipLongitude[0]
y2 = shipLongitude[1]
y3 = shipLongitude[2]
y4 = data[13][:2]
# print('\nShip Longitude: ', y1, y2, y3, y4)


# Ice Berg's Latitude
iceBergLatitude = [float(s) for s in re.findall(r'\b\d+\b', data[19])]
a1 = iceBergLatitude[0]
a2 = iceBergLatitude[1]
a3 = iceBergLatitude[2]
a4 = data[20]
# print('\nIce Berg Latitude: ', a1, a2, a3, a4)

# Ice Berg's Longitude
iceBergLongitude = [float(s) for s in re.findall(r'\b\d+\b', data[22])]
b1 = iceBergLongitude[0]
b2 = iceBergLongitude[1]
b3 = iceBergLongitude[2]
b4 = data[23][:2]
# print('\nIce Berg Longitude: ', b1, b2, b3, b4)

shipLatitudeResult = solve(x1, x2, x3, x4)
shipLongitudeResult = solve(y1, y2, y3, y4)
iceBergLatitudeResult = solve(a1, a2, a3, a4)
iceBergLongitudeResult = solve(b1, b2, b3, b4)


dist = 6875.0/2
dist = acos(sin(shipLatitudeResult) * sin(iceBergLatitudeResult) + cos(shipLatitudeResult)
            * cos(iceBergLatitudeResult) * cos(shipLongitudeResult - iceBergLongitudeResult)) * dist

print('\nThe distance to the iceberg:', round(dist, 2), 'miles.')
if dist < 100:
    print('DANGER!')

Edited by author 30.03.2021 16:37

Hello! I`ve got a code, equations must be right, but the result is different from sample. I don`t know what the problem is. Please, help!! My result is 45,28, whereas the sample`s one is 52,04.

static void Main(string[] args)
        {
            const double D = 6875;
            const double pi = 3.1415926535897932384626433;
            string trash;
            char[] separators = new[] { ' ', '^', '"', '\''};
            /* double shipx, shipy, shipz, icex, icey, icez; */
            for (int i = 0; i < 3; i++)
                trash = Console.ReadLine();
            var shipLat = Console.ReadLine().Split(separators);
            var shipLong = Console.ReadLine().Split(separators);
            trash = Console.ReadLine();
            var iceLat = Console.ReadLine().Split(separators);
            var iceLong = Console.ReadLine().Split(separators);
            trash = Console.ReadLine();

            double phi1 = (int.Parse(shipLat[0]) + (int.Parse(shipLat[1]) + int.Parse(shipLat[2]) / 60) / 60) * (pi / 180);
            double phi2 = (int.Parse(shipLong[1]) + (int.Parse(shipLong[2]) + int.Parse(shipLong[3]) / 60) / 60) * (pi / 180);
            if (shipLat[3] == "SL") phi1 = -phi1;
            if (shipLong[4] == "WL") phi2 = -phi2;

            double L1 = (int.Parse(iceLat[0]) + (int.Parse(iceLat[1]) + int.Parse(iceLat[2]) / 60)/60) * (pi / 180);
            double L2 = (int.Parse(iceLong[1]) + (int.Parse(iceLong[2]) + int.Parse(iceLong[3]) / 60)/60) * (pi / 180);
            if (iceLat[3] == "SL") L1 = -L1;
            if (iceLong[4] == "WL") L2 = -L2;

            double ans = Math.Acos(Math.Sin(phi1) * Math.Sin(L1) + Math.Cos(phi1) * Math.Cos(L1) * Math.Cos(L2-phi2));
            double dist = ans * D/2;

            Console.Write("The distance to the iceberg: ");
            Console.WriteLine("{0:0.00}", dist);
            if (100.00 - dist > 0.005) Console.WriteLine("DANGER!");
        }

Hello, everyone.
Just wanted to summarize some info about this problem.
Ok, my code got AC with following things in it:
1. My pi was 3.1415926535897932384626433 (perhaps it is enough)
2. I used this formula from wikipedia
deltaArc=acos(sin(phiA)*sin(phiB)+cos(phiA)*cos(phiB)*cos(deltaL));
distance = deltaArc*3437.5;
(see the first formula from wikipedia http://en.wikipedia.org/wiki/Great-circle_distance)
3. I used the following condition:
if(100.00-distance>0.005) printf("DANGER!\n");
Hope it will help somebody.

Всем привет. Пишу на с++. И возникла проблема с вводом широты и долготы без перехода на новую строку.
Выходит:

<X1>
^<X2>
'...

что не очень красиво. Хотелось бы так

<X1>^<X2>'<X3>" <NL/SL>

но не знаю как реализовать.

Спасибо.

Edited by author 07.03.2010 10:26

#include <iostream>
  #include <math.h>
  using namespace std;
  const long double D=6875;
  const long double pi=3.1415926535897932384626433;
  struct postype{
      long double x,y,z;
      };
  int x1,x2,x3,yy1,y2,y3;
 int sx1,sx2,sx3,syy1,sy2,sy3;
 char str[100000];
 char xstr[10],ystr[10],sxstr[10],systr[10];
 postype ship,ice;
 long double angle1,angle2;

 long double dis(double a,double b,double c,double d,double e,double f){
     a-=d;
     b-=e;
     c-=f;
     return sqrt(a*a+b*b+c*c);
     }

 int main(){
     for (int i=1;i<=3;++i) gets(str);
     scanf("%d^%d'%d\" %s\n",&x1,&x2,&x3,&xstr);
     scanf("and %d^%d'%d\" %s\n",&yy1,&y2,&y3,&ystr);
     gets(str);
     scanf("%d^%d'%d\" %s\n",&sx1,&sx2,&sx3,&sxstr);
     scanf("and %d^%d'%d\" %s\n",&syy1,&sy2,&sy3,&systr);
     gets(str);

     double a=x1,b=x2,c=x3;
     angle1=a*3600+b*60.0+c;
     angle1/=3600.0*180;
     angle1*=pi;
     if (xstr[0]=='S') angle1=-angle1;
     a=yy1;b=y2;c=y3;
     angle2=a*3600+b*60.0+c;
     angle2/=3600.0*180;
     angle2*=pi;
     if (ystr[0]=='W') angle2=-angle2;
     ship.x=D/2*cos(angle1)*cos(angle2);
     ship.y=D/2*cos(angle1)*sin(angle2);
     ship.z=D/2*sin(angle1);

     a=sx1,b=sx2,c=sx3;
     angle1=a*3600+b*60+c;
     angle1/=3600.0*180;
     angle1*=pi;
     if (sxstr[0]=='S') angle1=-angle1;
     a=syy1;b=sy2;c=sy3;
     angle2=a*3600+b*60+c;
     angle2/=3600.0*180;
     angle2*=pi;
     if (systr[0]=='W') angle2=-angle2;
     ice.x=D/2*cos(angle1)*cos(angle2);
     ice.y=D/2*cos(angle1)*sin(angle2);
     ice.z=D/2*sin(angle1);

     long double linedis=dis(ship.x,ship.y,ship.z,ice.x,ice.y,ice.z);
     linedis/=2;
     long double AA=asin(linedis*2/D)*2;
     long double ans=AA;
     ans=ans*D/2;

     printf("The distance to the iceberg: ");
     cout.precision(2);
     cout<<fixed;
     cout<<ans;
     printf(" miles.\n");
     if (100.00-ans>0.005) printf("DANGER!");
     }

  just because R=6875*(1.0/2.0) instead of R=6875/2  hope it's helpful to you.

{No.1030 Titanic.}
Const
     pi=3.1415926535897932384626433832795;
Var
     Char1,NS1,EW1,NS2,EW2:Char;
     A1,B1,C1,D1,E1,F1,A2,B2,C2,D2,E2,F2:Integer;
     SqrD,Alpha,L,X1,Y1,Z1,X2,Y2,Z2:Real;
Function ReadNum:Integer;
Var
     Str1:String;
     Code,Num:Integer;
     Char1:Char;
Begin
     Str1:='##';
     Read(Str1[1]); Read(Str1[2]);
     Read(Char1);
     If Char1 In ['0'..'9'] Then
          Str1:=Str1+Char1;
     Val(Str1,Num,Code);
     ReadNum:=Num;
End;
Procedure Cal(Theta1,Theta2:Real;NS,EW:Char;Var X,Y,Z:Real);
Begin
     If NS='N' Then
          Z:=Sin(Theta1)
     Else Z:=-Sin(Theta1);
     X:=Cos(Theta2)*Cos(Theta1);
     If EW='E' Then
          Y:=Sin(Theta2)*Cos(Theta1)
     Else Y:=-Sin(Theta2)*Cos(Theta1);
End;
Begin
     ReadLn;
     ReadLn;
     ReadLn;

     A1:=ReadNum;
     B1:=ReadNum;
     C1:=ReadNum;
     Read(Char1);
     Read(NS1);
     ReadLn;

     Read(Char1); Read(Char1); Read(Char1); Read(Char1);
     D1:=ReadNum;
     E1:=ReadNum;
     F1:=ReadNum;
     Read(Char1);
     Read(EW1);
     ReadLn;

     ReadLn;

     A2:=ReadNum;
     B2:=ReadNum;
     C2:=ReadNum;
     Read(Char1);
     Read(NS2);
     ReadLn;

     Read(Char1); Read(Char1); Read(Char1); Read(Char1);
     D2:=ReadNum;
     E2:=ReadNum;
     F2:=ReadNum;
     Read(Char1);
     Read(EW2);
     ReadLn;
     ReadLn;

     Cal((((C1/60)+B1)/60+A1)/180*pi,(((F1/60)
+E1)/60+D1)/180*pi,NS1,EW1,X1,Y1,Z1);
     Cal((((C2/60)+B2)/60+A2)/180*pi,(((F2/60)
+E2)/60+D2)/180*pi,NS2,EW2,X2,Y2,Z2);

     If (Abs(X1+X2)<1E-7) And (Abs(Y1+Y2)<1E-7) And (Abs(Z1+Z2)<1E-7)
Then
          Alpha:=pi
     Else Begin
          SqrD:=Sqr(X1-X2)+Sqr(Y1-Y2)+Sqr(Z1-Z2);
          Alpha:=Arctan(Sqrt(SqrD)/2/Sqrt(1-SqrD/4))*2;
     End;
     L:=Alpha*6875/2;
     WriteLn('The distance to the iceberg: ',L:0:2,' miles.');
     If 100-L>1E-7 Then
          WriteLn('DANGER!');
End.

My program had WA Test#7. Last two lines were:
    printf("The distance to the iceberg: %.2lf miles.\n",ans);
    if (ans<99.999) printf("DANGER!");
But when I changed only the last one:
    if (ans<99.995) printf("DANGER!");
I got AC!

(Now I think, that I should compare with 100 miles not answer, but it with two digits: so 99.996 is 100.00, but 99.994 is 99.99.)

Can anyone give me a test？Thanks a lot.

I aways WA,but I cannot find the error.Can someone help me?

#include<stdio.h>
#include<math.h>
#include<algorithm>

using namespace std;

#define PI 3.1415926535897932384626433

int lat1, lat2, lat3, lon1, lon2, lon3, trash;
char latc, lonc;

long double latf, lats, lonf, lons;
long double sq(double x){
  return x*x;
}

int main(void){
  scanf("Message #%d.\nReceived at %d:%d:%d.\nCurrent ship’s coordinates are\n%d^%d'%d\" %cL\nand %d^%d'%d\" %cL.\n",
         &trash, &trash, &trash, &trash, &lat1, &lat2, &lat3, &latc, &lon1, &lon2, &lon3, &lonc);
  lats = (latc=='N'?1:-1)*(lat1 + (lat2 + lat3/60.0)/60.0)*PI/180.0;
  lons = (lonc=='W'?-1:1)*(lon1 + (lon2 + lon3/60.0)/60.0)*PI/180.0;


  scanf("An iceberg was noticed at\n%d^%d'%d\" %cL\nand %d^%d'%d\" %cL.",
         &lat1, &lat2, &lat3, &latc, &lon1, &lon2, &lon3, &lonc);
  latf = (latc=='N'?1:-1)*(lat1 + (lat2 + lat3/60.0)/60.0)*PI/180.0;
  lonf = (lonc=='W'?-1:1)*(lon1 + (lon2 + lon3/60.0)/60.0)*PI/180.0;

  double dlon = lonf - lons, dlat = latf - lats;

  double a = acos(sin(lats)*sin(latf) + cos(lats)*cos(latf)*cos(dlon));
  double len =  3437.5*a;
  printf("The distance to the iceberg: %.2lf miles.\n", len);
  if(100.00-len>0.005)
    printf("DANGER!\n");
  return 0;
}

Am I wright about input?

import java.util.*;
import java.text.*;

public class zad1030
    {
        public static void main(String[] args)
            {
                double alpS1, alpS2, alpD1, alpD2, l, r=6875/2.0, a, b, c;
                String s, res, sh="0123456789";
                Scanner cin=new Scanner(System.in);
                NumberFormat f=NumberFormat.getInstance(Locale.UK);
                f.setMinimumFractionDigits(2);
                f.setMaximumFractionDigits(2);
                while (cin.hasNext())
                    {
                        cin.nextLine();
                        cin.nextLine();
                        cin.nextLine();
                        s=cin.nextLine();
                        while (sh.indexOf(s.substring(0, 1))<0)
                            {
                                s=s.substring(1);
                            }
                        a=Integer.parseInt(s.substring(0, s.indexOf("^")));
                        s=s.substring(s.indexOf("^")+1);
                        b=Integer.parseInt(s.substring(0, s.indexOf("'")));
                        s=s.substring(s.indexOf("'")+1);
                        c=Integer.parseInt(s.substring(0, s.indexOf("\"")));
                        s=s.substring(s.indexOf("\"")+1);
                        alpS1=Math.toRadians(a+b/60.0+c/3600.0);
                        if (s.substring(0, 3)==" SL") alpS1=-alpS1;
                        s=cin.nextLine();
                        while (sh.indexOf(s.substring(0, 1))<0)
                            {
                                s=s.substring(1);
                            }
                        a=Integer.parseInt(s.substring(0, s.indexOf("^")));
                        s=s.substring(s.indexOf("^")+1);
                        b=Integer.parseInt(s.substring(0, s.indexOf("'")));
                        s=s.substring(s.indexOf("'")+1);
                        c=Integer.parseInt(s.substring(0, s.indexOf("\"")));
                        s=s.substring(s.indexOf("\"")+1);
                        alpD1=Math.toRadians(a+b/60.0+c/3600.0);
                        if (s.substring(0, 3)==" WL") alpD1=-alpD1;
                        cin.nextLine();
                        s=cin.nextLine();
                        while (sh.indexOf(s.substring(0, 1))<0)
                            {
                                s=s.substring(1);
                            }
                        a=Integer.parseInt(s.substring(0, s.indexOf("^")));
                        s=s.substring(s.indexOf("^")+1);
                        b=Integer.parseInt(s.substring(0, s.indexOf("'")));
                        s=s.substring(s.indexOf("'")+1);
                        c=Integer.parseInt(s.substring(0, s.indexOf("\"")));
                        s=s.substring(s.indexOf("\"")+1);
                        alpS2=Math.toRadians(a+b/60.0+c/3600.0);
                        if (s.substring(0, 3)==" SL") alpS2=-alpS2;
                        s=cin.nextLine();
                        while (sh.indexOf(s.substring(0, 1))<0)
                            {
                                s=s.substring(1);
                            }
                        a=Integer.parseInt(s.substring(0, s.indexOf("^")));
                        s=s.substring(s.indexOf("^")+1);
                        b=Integer.parseInt(s.substring(0, s.indexOf("'")));
                        s=s.substring(s.indexOf("'")+1);
                        c=Integer.parseInt(s.substring(0, s.indexOf("\"")));
                        s=s.substring(s.indexOf("\"")+1);
                        alpD2=Math.toRadians(a+b/60.0+c/3600.0);
                        if (s.substring(0, 3)==" WL") alpD2=-alpD2;
                        l=r*Math.acos(Math.sin(alpS1)*Math.sin(alpS2)+Math.cos(alpS1)*Math.cos(alpS2)*Math.cos(alpD1-alpD2));
                        l=Math.round(l*100)/100.0;
                        res=f.format(l);
                        System.out.println("The distance to the iceberg: "+res+" miles.");
                        if (100.0-l>=0.01) System.out.println("DANGER!");
                        cin.nextLine();
                    }
            }
    }

Edited by author 12.02.2010 21:06

Maybe the problem is in acuracy...
but I use pi=2.0*acosl(0.0)...
Maybe it's printing DANGER!
but I use
if (result<99.995) printf("DANGER!\n");
Any ideas?

I've got several WA on this problem. Could somebody tell me
if I should use this equation to count :

angle = acos(cos(as)*cos(bs)*cos(ai)*cos(bi)+cos(as)*sin(bs)
*cos(ai)*sin(bi)+sin(as)*sin(ai));

where as,bs are altitude and longitude of ship, and ai,bi
of iceberg ???

And could I use this:
ang2 = [ ( (secs/60)+mins )/60 + hrs ] * PI/180
to get the radian angle from given coordinates (hh^mm'ss'')

Please help!??!

why my answer is 52.14?

The main idea is:
w1,w2,l1,l2.

r:=6875/2;
dist:=r*arccos(sin(w1)*sin(w2)+cos(w1)*cos(w2)*cos(l2-l1));