Compilare: user.cpp: In function ‘long long int solve()’: user.cpp:21:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf(" %s", s); n = strlen(s); ^ user.cpp: In function ‘int main()’: user.cpp:67:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("brackets2.in", "r", stdin); ^ user.cpp:68:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("brackets2.out", "w", stdout); ^ user.cpp:69:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^