Compilare: user.cpp: In function ‘int main()’: user.cpp:86:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lcdr.in", "r", stdin); ^ user.cpp:87:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lcdr.out", "w", stdout); ^ user.cpp:89:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d\n", &n, &m, &Q); ^ user.cpp:93:18: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(A+1); ^ user.cpp:107:49: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d\n", &L, &C, &L1, &L2); ^ /tmp/ccrSifvT.o: In function `main': user.cpp:(.text.startup+0x90): warning: the `gets' function is dangerous and should not be used.