void buy_souvenirs(int N, long long P0) {
transaction(P0 - 1);
}
컴파일 시 표준 에러 (stderr) 메시지
souvenirs.cpp: In function 'void buy_souvenirs(int, long long int)':
souvenirs.cpp:2:6: error: 'transaction' was not declared in this scope
2 | transaction(P0 - 1);
| ^~~~~~~~~~~