Compilare: user.cpp: In function ‘int main()’: user.cpp:49:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0 ; i < queries.size() ; ++i) ^ user.cpp:51:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (j < events.size() && events[j].first < queries[i].first) ^ user.cpp:16:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nori.in" , "r" , stdin); ^ user.cpp:17:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nori.out" , "w" , stdout); ^ user.cpp:19:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &n); ^ user.cpp:23:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &x); ^ user.cpp:24:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &y); ^ user.cpp:25:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &r); ^ user.cpp:37:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &m); ^ user.cpp:41:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &x); ^ user.cpp:42:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &y); ^