Compilare: main.cpp: In function 'void del(int, int)': main.cpp:36:14: warning: variable 'it' set but not used [-Wunused-but-set-variable] auto it = f[bucket_id].find(x); ^~ main.cpp: In function 'int main()': main.cpp:92:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("arbore.in", "r", stdin); ^ main.cpp:93:44: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("arbore.out", "w", stdout); ^ main.cpp:95:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &q); ^ main.cpp:99:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &b); ^ main.cpp:125:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &tp); ^ main.cpp:129:47: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &x); ^ main.cpp:146:40: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^