Three word location
Three word location
You are encouraged to solve this task according to the task description, using any language you may know.
You are encouraged to solve this task according to the task description, using any language you may know.
Three Word Location. Display a location on the Earth with three words derived from a latitude longitude pair. For: latitude = 28.3852 longitude = -81.5638 Display: W18497 W11324 W01322 Implementation: Build a synthetic word array of 28126, 6 character words in the form W00000 thru W28125. Convert latitude and longitude into positive integers. Build a 43 bit integer containing latitude (21 bits) and longitude (22 bits). Isolate most significant 15 bits for word 1 index. Isolate next 14 bits for word 2 index. Isolate next 14 bits for word 3 index. Fetch each word from the word array. Display the words. Reverse the procedure and display the original latitude and longitude.
Symsyn
<lang Symsyn> | Three Word Location - convert latitude and longitude to three words
lat : 28.3852 lon : -81.5638
| build word array W00000 ... W28125
i if i <= 28125 ~ i $r #$r szr 'W00000' $t (6-szr) szr szr #$t + $r $t + $t $wordarray + i goif endif
| make latitude and longitude positive integers
{lat * 10000 + 900000} ilat {lon * 10000 + 1800000} ilon
| build 43 bit integer containing latitude (21 bits) and longitude (22 bits)
ilat latlon shl latlon 22 + ilon latlon
| isolate most significant 15 bits for word 1 index | next 14 bits for word 2 index | next 14 bits for word 3 index
latlon:42:15 w1 latlon:27:14 w2 latlon:13:14 w3
| fetch each word from word array
(w1*6+1) w1 $wordarray.w1 $w1 6 (w2*6+1) w2 $wordarray.w2 $w2 6 (w3*6+1) w3 $wordarray.w3 $w3 6
| display words
"$w1 ' ' $w2 ' ' $w3" []
| reverse the procedure
| look up each word
call bsearch 0 28125 $w1 result w1index
call bsearch 0 28125 $w2 result w2index
call bsearch 0 28125 $w3 result w3index
| build the latlon integer from the word indexes
w1index latlon shl latlon 14 + w2index latlon shl latlon 14 + w3index latlon
| isolate the latitude and longitude
latlon:21:22 ilon latlon:42:21 ilat
| convert back to floating point values
{(ilon - 1800000) / 10000} lon {(ilat - 900000) / 10000} lat
| display values
"'latitude = ' lat ' longitude = ' lon" []
stop
bsearch
param L H $word if L <= H ((L + H) shr 1) M (M*6+1) I $wordarray.I $w 6 if $w > $word - 1 M H else if $w < $word + 1 M L else return M endif endif goif endif return -1
</lang>