I added two examples of large values to the sample and fixed tests in all the translations.

Will do when I get a chance, probably Tuesday.

Have another suggestion (let you see): as I clicked several times before passing (waiting for the random tests NOT to generate such a case).. it means that invalid solutions may pass..

you should add such a case in the fixed tests. And may be in the first given tests.

The condition "c to be less than int max" is really redundant, since all variables are ints.

I did add the following text to the description, which hopefully will clarify things:

Note: Although a, b, c are all integers, it's possible that their squares can exceed the integer bound in a statically-typed language. Such solutions should be included.

I know why my first sol didn't pass (as well as ... why my accepted solution passes not 100% of the time)...
The condition for c to be less than int max in c++(in c++, use std::numeric_limits::max()) is never mentioned in the description....
Make a special description in

Hi eurydice5717,

I believe I have fixed the issue. Please try again and let me know.

Regards,

brodiemark

Trying C++, having a problem with random cases.

Failed for diff = 3514, low = 279314, high = 401782
Expected: equal to [  ]
Actual: [ [ 304696, 374643, 378157 ], [ 306740, 552471, 555985 ], [ 312230, 424864, 428378 ], [ 312258, 427352, 430866 ], [ 313234, 514216, 517730 ], [ 313262, 516712, 520226 ], [ 319362, 454680, 458194 ], [ 319684, 483959, 487473 ], [ 319864, 500339, 503853 ], [ 320186, 529664, 533178 ], [ 331446, 351440, 354954 ], [ 332700, 469943, 473457 ], [ 332952, 493811, 497325 ], [ 352814, 598504, 602018 ], [ 392798, 562616, 566130 ], [ 397434, 472768, 476282 ], [ 398438, 586464, 589978 ] ]

You can verify that the actual results are triples satisfying the requirements ;-)
How can the expected result be '[]' ??

??
Whenever encode or decode is called, my code prints in order input string and output string..
I Will check.

but... doesnt explain the output auab^... of the expected value ??

can't verify due to not having solved in c++/not seeing your code
but - this looks to me like you're mixing up different test cases, ie. you're showing the input of one test and the expected output of a different one. be careful with how you print and how you read the output.

duplicate of this suggestion

Does that edge case (n=1, k=10) still exist? Right now, the description says (0 ≤ k ≤ n^2).