Base-16 representation
- Task
Show in decimal notation all positive integers (less than 501) which, when converted to base-16 notation, cannot be written without using at least one hexadecimal digit ('a' to 'f').
C++
<lang cpp>#include <iomanip>
- include <iostream>
// Returns true if the hexadecimal representation of n contains at least one // non-decimal digit. bool nondecimal(unsigned int n) {
for (; n > 0; n >>= 4) {
if ((n & 0xF) > 9)
return true;
}
return false;
}
int main() {
unsigned int count = 0;
for (unsigned int n = 0; n < 501; ++n) {
if (nondecimal(n)) {
++count;
std::cout << std::setw(3) << n << (count % 15 == 0 ? '\n' : ' ');
}
}
std::cout << "\n\n" << count << " such numbers found.\n";
}</lang>
- Output:
10 11 12 13 14 15 26 27 28 29 30 31 42 43 44 45 46 47 58 59 60 61 62 63 74 75 76 77 78 79 90 91 92 93 94 95 106 107 108 109 110 111 122 123 124 125 126 127 138 139 140 141 142 143 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 266 267 268 269 270 271 282 283 284 285 286 287 298 299 300 301 302 303 314 315 316 317 318 319 330 331 332 333 334 335 346 347 348 349 350 351 362 363 364 365 366 367 378 379 380 381 382 383 394 395 396 397 398 399 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 301 such numbers found.
Raku
Yet another poorly specced, poorly named, trivial task.
How many integers in base 16 cannot be written without using a hexadecimal digit? All of them. Or none of them.
Base 16 is not hexadecimal. Hexadecimal is an implementation of base 16.
<lang perl6>use Base::Any; set-digits <⑩ ⑪ ⑫ ⑬ ⑭ ⑮ ⑯ ⑰ ⑱ ⑲ ⑳ ㉑ ㉒ ㉓ ㉔ ㉕>; say (7**35).&to-base(16);
- ⑭㉒⑱⑩⑰⑰⑳⑮⑱⑳⑩⑳⑱㉒㉑⑰㉒⑫⑭⑲⑯⑩㉔⑮⑰</lang>
How many of those glyphs are decimal digits? And yet it is in base 16, albeit with non-standard digit glyphs. So they all can be written without using a hexadecimal digit.
But wait a minute; is 2 a hexadecimal digit? Why yes, yes it is. So none of them can be written in hexadecimal without using a hexadecimal digit.
Bah. Show which when written in base 16, contain a digit glyph with a value greater than 9:
<lang perl6>say (0..500).grep( { any |.map: { .polymod(16 xx *) »>» 9 } } ).batch(20)».fmt('%3d').join: "\n";</lang>
- Output:
10 11 12 13 14 15 26 27 28 29 30 31 42 43 44 45 46 47 58 59 60 61 62 63 74 75 76 77 78 79 90 91 92 93 94 95 106 107 108 109 110 111 122 123 124 125 126 127 138 139 140 141 142 143 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 266 267 268 269 270 271 282 283 284 285 286 287 298 299 300 301 302 303 314 315 316 317 318 319 330 331 332 333 334 335 346 347 348 349 350 351 362 363 364 365 366 367 378 379 380 381 382 383 394 395 396 397 398 399 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500
Ring
, <lang ring> see "working..." + nl baseList = ["a","b","c","d","e","f"] row = 1 limit = 500
for n = 1 to limit
num = 0
flag = 1
hex = hex(n)
lenHex = len(hex)
for m = 1 to lenHex
ind = find(baseList,hex[m])
if ind < 1
num = num + 1
ok
next
if num != lenHex
row = row + 1
see "" + n + " "
if row%10 = 0
see nl
ok
ok
next
see nl + "done..." + nl </lang>
- Output:
working... 10 11 12 13 14 15 26 27 28 29 30 31 42 43 44 45 46 47 58 59 60 61 62 63 74 75 76 77 78 79 90 91 92 93 94 95 106 107 108 109 110 111 122 123 124 125 126 127 138 139 140 141 142 143 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 266 267 268 269 270 271 282 283 284 285 286 287 298 299 300 301 302 303 314 315 316 317 318 319 330 331 332 333 334 335 346 347 348 349 350 351 362 363 364 365 366 367 378 379 380 381 382 383 394 395 396 397 398 399 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 done...
Wren
<lang ecmascript>import "/fmt" for Conv, Fmt
var nondecimal = "abcdef" var c = 0 for (i in 0..500) {
var hex = Conv.hex(i)
if (hex.any { |c| nondecimal.contains(c) }) {
Fmt.write("$3s ", i)
c = c + 1
if (c % 15 == 0) System.print()
}
} System.print("\n\n%(c) such numbers found.")</lang>
- Output:
10 11 12 13 14 15 26 27 28 29 30 31 42 43 44 45 46 47 58 59 60 61 62 63 74 75 76 77 78 79 90 91 92 93 94 95 106 107 108 109 110 111 122 123 124 125 126 127 138 139 140 141 142 143 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 266 267 268 269 270 271 282 283 284 285 286 287 298 299 300 301 302 303 314 315 316 317 318 319 330 331 332 333 334 335 346 347 348 349 350 351 362 363 364 365 366 367 378 379 380 381 382 383 394 395 396 397 398 399 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 301 such numbers found.
XPL0
Borrowed masking concept from C++, which was much more elegant than my first solution. <lang XPL0>func HasHex(N); int N; [while N do
[if (N&$F) > 9 then return true; N:= N>>4];
return false; ];
int N, Cnt; [Cnt:= 0; for N:= 1 to 500 do
[if HasHex(N) then
[if N<100 then ChOut(0, ^ );
IntOut(0, N);
Cnt:= Cnt+1;
if rem(Cnt/20) = 0 then CrLf(0) else ChOut(0, ^ );
];
];
CrLf(0); IntOut(0, Cnt); Text(0, " such numbers found."); CrLf(0); ]</lang>
- Output:
10 11 12 13 14 15 26 27 28 29 30 31 42 43 44 45 46 47 58 59 60 61 62 63 74 75 76 77 78 79 90 91 92 93 94 95 106 107 108 109 110 111 122 123 124 125 126 127 138 139 140 141 142 143 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 266 267 268 269 270 271 282 283 284 285 286 287 298 299 300 301 302 303 314 315 316 317 318 319 330 331 332 333 334 335 346 347 348 349 350 351 362 363 364 365 366 367 378 379 380 381 382 383 394 395 396 397 398 399 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 301 such numbers found.