I passed:), Thanks.

thanks. I might be the second one to pass this test by C++ :)

C++ test cases are wrong.
For example, in python, the naive and correct solution of Avanta's Kata,
print(triangle("GBRBBGBGBRGBRBRGBGBBRGGGGBBRGRRBRGBRBBGBBRBRGRBRBRRBGGRRGRRBGGRGRBBRBGRGBBBRGBBRBBRRGGGRRRRGBGRRGRRRBBRGGRBRBBGBGBGRGRGGRBRGRGGBGBGRGBGGBGGRRRBRRGRBBBGRBBGRGRGBRBBBBGRBGRBBGRBBGRBGRGBBRRBGBRGBRRGRRRRGGRRRRRBRGBGGGGGBRGGBRRGGGRBBGRGRRGGGBRGGGRRBBGGBRRGRGRGRRGBRGRRBBGGRRRBGRRRRBBRBRGRBGRBRBBGGRGGRGRRGRGBGGRBRBBGRBBBGBGBBRRGRRRBGRRBGGBBBBBGBRBRBGBGBGGBBBGGBGRRBRRRBBBBBBRBRBBBBGRGRBGRBBGGGBRRBRRBGRBRRRBRRGBRGGBGRRGRRRBGBRBRRRRBRBRGGBBBBRBRGBGBRGRRGRBBGGRBBRBBGBGBBGGGGGBRRGRRBGRGBRRRBGRGBBGRBRRGBGGGBRGBBGRBGRGRGBGRGBBGBRBGRBRRGBGGRRGRBGRGBBGRBRGGBRBBRGGBGBBRGBGBBRGBGBRRGRGRRBBGBBRGBBRGBRBGBGBBBRBRBRBGRGBGGGBGBGBGGRBRGGBGGGGRBGGBBGRBRRGGBGRGRRRGGRBRBGBGGGGGRRGBBBBBRGRRRGBRBRBRGBGGGGRBBBBGRRRRRGBGBGGRRGGRBRRGBBGRRGGGGRBRGRRGGRRGBBBRGRRRGBBGBRBRBGBGBBGGBBRBGGGGRBBBBRRGRRBRGBGGGRRGRBBRBRRGBBRBGRR"))
will print out 'G'.
As for C++, I print out the random test case which is exactly the long string above. The required answer is 'B' instead of 'G'.
Hence, I believe there is something wrong with the C++ test cases.