Compilare: user.cpp: In function ‘void read(int)’: user.cpp:45:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^ user.cpp: In function ‘int main()’: user.cpp:52:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("disjoint.in", "r", stdin); ^ user.cpp:53:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("disjoint.out", "w", stdout); ^ user.cpp:55:9: warning: ‘sets’ is used uninitialized in this function [-Wuninitialized] read(sets), read(queries); ^ user.cpp:55:21: warning: ‘queries’ is used uninitialized in this function [-Wuninitialized] read(sets), read(queries); ^ user.cpp:50:24: warning: ‘task’ may be used uninitialized in this function [-Wmaybe-uninitialized] int sets, queries, task, x, y; ^ user.cpp:50:30: warning: ‘x’ may be used uninitialized in this function [-Wmaybe-uninitialized] int sets, queries, task, x, y; ^ user.cpp:50:33: warning: ‘y’ may be used uninitialized in this function [-Wmaybe-uninitialized] int sets, queries, task, x, y; ^