Box the compass: Difference between revisions

=={{header|C++}}==

Using the Boost libraries

{{libheader|Boost}}

<lang C++>#include <map>;

#include <string>;

#include <vector>

#include <boost/assign/list_inserter.hpp>

#include <boost/assign/std/vector.hpp>

#include <boost/format.hpp>

#include <boost/foreach.hpp>

#include <iostream>;

#include <math.h>

using std::string;

using namespace boost::assign;

using boost::format;

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 bool first_time(true);

static std::map<int, string> points;

if (first_time){

first_time = false;

insert (points)

( 1, "N") ( 2, "NbE") ( 3, "NNE") ( 4, "NEbN")

( 5, "NE") ( 6, "NEbE") ( 7, "ENE") ( 8, "EbN")

( 9, "E") (10, "EbS") (11, "ESE") (12, "SEbE")

(13, "SE") (14, "SEbS") (15, "SSE") (16, "SbE")

(17, "S") (18, "SbW") (19, "SSW") (20, "SWbS")

(21, "SW") (22, "SWbW") (23, "WSW") (24, "WbS")

(25, "W") (26, "WbN") (27, "WNW") (28, "NWbW")

(29, "NW") (30, "NWbN") (31, "NNW") (32, "NbW");

}

return points[i];

}

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()

{

std::vector<float> headings;

headings += 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;

format f("%1$4d %2$-25s %3%");

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;

}</lang>

Output:

<pre>

1 North 0

2 North by east 16.87

3 North-northeast 16.88

4 Northeast by north 33.75

5 Northeast 50.62

6 Northeast by east 50.63

7 East-northeast 67.5

8 East by north 84.37

9 East 84.38

10 East by south 101.25

11 East-southeast 118.12

12 Southeast by east 118.13

13 Southeast 135

14 Southeast by south 151.87

15 South-southeast 151.88

16 South by east 168.75

17 South 185.62

18 South by west 185.63

19 South-southwest 202.5

20 Southwest by south 219.37

21 Southwest 219.38

22 Southwest by west 236.25

23 West-southwest 253.12

24 West by south 253.13

25 West 270

26 West by north 286.87

27 West-northwest 286.88

28 Northwest by west 303.75

29 Northwest 320.62

30 Northwest by north 320.63

31 North-northwest 337.5

32 North by west 354.37

1 North 354.38

</pre>