Compilare: user.cpp: In function ‘int main()’: user.cpp:46:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < r.size(); i++) ^ user.cpp:49:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < r[i].size(); j++) ^ user.cpp:20:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cinema.in", "r", stdin); ^ user.cpp:21:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cinema.out", "w", stdout); ^ user.cpp:23:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:25:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^