There be many a land lubber that knows naught of the pirate ways and gives direction by degree!
They know not how to box the compass!



Task description

 Create a function that takes a heading in degrees and returns the correct 32-point compass heading.
 Use the function to print and display a table of Index, Compass point, and Degree; rather like the corresponding columns from, the first table of the wikipedia article, but use only the following 33 headings as input:
[0.0, 16.87, 16.88, 33.75, 50.62, 50.63, 67.5, 84.37, 84.38, 101.25, 118.12, 118.13, 135.0, 151.87, 151.88, 168.75, 185.62, 185.63, 202.5, 219.37, 219.38, 236.25, 253.12, 253.13, 270.0, 286.87, 286.88, 303.75, 320.62, 320.63, 337.5, 354.37, 354.38]. (They should give the same order of points but are spread throughout the ranges of acceptance).


Notes;
 The headings and indices can be calculated from this pseudocode:
for i in 0..32 inclusive:
    heading = i * 11.25
    case i %3:
      if 1: heading += 5.62; break
      if 2: heading -= 5.62; break
    end
    index = ( i mod 32) + 1
 The column of indices can be thought of as an enumeration of the thirty two cardinal points (see talk page)..


#include <string>
#include <boost/array.hpp>
#include <boost/assign/list_of.hpp>
#include <boost/format.hpp>
#include <boost/foreach.hpp>
#include <iostream>
#include <math.h>
using std::string;
using namespace boost::assign;
 
int get_Index(float angle)
{
   return static_cast<int>(floor(angle / 11.25 +0.5 )) % 32 + 1;
}
 
string get_Abbr_From_Index(int i)
{
    static boost::array<std::string, 32> points(list_of
            ("N")("NbE")("NNE")("NEbN")("NE")("NEbE")("ENE")("EbN")
            ("E")("EbS")("ESE")("SEbE")("SE")("SEbS")("SSE")("SbE")
            ("S")("SbW")("SSW")("SWbS")("SW")("SWbW")("WSW")("WbS")
            ("W")("WbN")("WNW")("NWbW")("NW")("NWbN")("NNW")("NbW"));
    return points[i-1];
}
 
string Build_Name_From_Abbreviation(string a)
{
    string retval;
    for (int i = 0; i < a.size(); ++i){
        if ((1 == i) && (a[i] != 'b') && (a.size() == 3)) retval += "-";
        switch (a[i]){
            case 'N' : retval += "north"; break; 
            case 'S' : retval += "south"; break; 
            case 'E' : retval += "east";  break; 
            case 'W' : retval += "west";  break; 
            case 'b' : retval += " by ";  break;
        }
    }
    retval[0] = toupper(retval[0]);
    return retval;
}
 
int main()
{
    boost::array<float,33> headings(list_of
            (0.0)(16.87)(16.88)(33.75)(50.62)(50.63)(67.5)(84.37)(84.38)(101.25)
            (118.12)(118.13)(135.0)(151.87)(151.88)(168.75)(185.62)(185.63)(202.5)
            (219.37)(219.38)(236.25)(253.12)(253.13)(270.0)(286.87)(286.88)(303.75)
            (320.62)(320.63)(337.5)(354.37)(354.38));
    int i;
    boost::format f("%1$4d %2$-20s %3$_7.2f");
 
    BOOST_FOREACH(float a, headings)
    {
        i = get_Index(a);
        std::cout << f % i %  Build_Name_From_Abbreviation(get_Abbr_From_Index(i)) % a << std::endl;
    }
    return 0;
}