Compilare: user.cpp: In function ‘int main()’: user.cpp:15:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("dinti.in", "r", stdin); ^ user.cpp:16:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("dinti.out", "w", stdout); ^ user.cpp:18:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d%d\n", &n, &m, &l); ^ user.cpp:19:13: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets (A); ^ user.cpp:43:17: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets (B); ^ /tmp/cceLdhnn.o: In function `main': user.cpp:(.text.startup+0x7a): warning: the `gets' function is dangerous and should not be used.