Developer Documentation

int2roman.cc
1 #include <OpenMesh/Core/System/config.hh>
2 #if defined(OM_CC_MIPS)
3 # include <assert.h>
4 #else
5 # include <cassert>
6 #endif
7 #include "int2roman.hh"
8
9
10 std::string int2roman( size_t decimal, size_t length )
11 {
12 assert( decimal > 0 && decimal < 1000 );
13
14 const size_t nrows = 4;
15 const size_t ncols = 4;
16
17 static size_t table_arabs[ nrows ][ ncols ] = { { 1000, 1000, 1000, 1000 },
18 { 900, 500, 400, 100 },
19 { 90, 50, 40, 10 },
20 { 9, 5, 4, 1 } };
21
22 static char *table_romans[ nrows ][ ncols ] = { { "M", "M", "M", "M" },
23 { "CM", "D", "CD", "C" },
24 { "XC", "L", "XL", "X" },
25 { "IX", "V", "IV", "I" } };
26
27 size_t power; // power of ten
28 size_t index; // Indexes thru values to subtract
29
30 std::string roman;
31
32 roman.reserve(length);
33
34 roman[ 0 ] = '\0';
35
36 for ( power = 0; power < nrows; power++ )
37 for ( index = 0; index < ncols; index++ )
38 while ( decimal >= table_arabs[ power ][ index ] )
39 {
40 roman += table_romans[ power ][ index ];
41 decimal -= table_arabs[ power ][ index ];
42 }
43
44 return roman;
45 }