Compilare: user.cpp: In function ‘int main()’: user.cpp:3:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] #define for0(i, n) for(int i = 0; i < n; i++) ^ user.cpp:107:9: note: in expansion of macro ‘for0’ for0(j, s.size()) ^ user.cpp:89:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ninjago.in", "r", stdin); ^ user.cpp:90:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ninjago.out", "w", stdout); ^