Strange numbers: Difference between revisions

=={{header|FreeBASIC}}==

<lang freebasic>function is_strange( n as ulongint ) as boolean

dim as uinteger d, ld, a

if n<10 then return true 'arbitrary, but makes the recursion easier

d = n mod 10

ld = (n mod 100) \ 10

a = abs(d - ld)

if a = 2 or a = 3 or a = 5 or a = 7 then return is_strange(n\10) else return false

end function

print "Strange numbers between 100 and 500"

for n as uinteger = 101 to 499

if is_strange(n) then print n;" ";

next n

print : print

dim as integer c = 0

for n as ulongint = 1000000000 to 1999999999

if is_strange(n) then c+=1

next n

print using "There are ####### 10-digit strange numbers beginning with 1.";c</lang>

{{out}}<pre>

Strange numbers between 100 and 500

130 131 135 136 138 141 142 146 147 149 161 163 164 168 169 181 183 185 186 202 203 205 207 241 242 246 247 249 250 252 253 257 258 270 272 274 275 279 292 294 296 297 302 303 305 307 313 314 316 318 350 352 353 357 358 361 363 364 368 369 381 383 385 386 413 414 416 418 420 424 425 427 429 461 463 464 468 469 470 472 474 475 479 492 494 496 497

There are 853423 10-digit strange numbers beginning with 1.</pre>