Compilare: user.cpp: In function ‘int main()’: user.cpp:25:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("insule.in", "r", stdin); ^ user.cpp:26:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("insule.out", "w", stdout); ^ user.cpp:28:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%hd%hd", &n, &m); ^ user.cpp:29:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("\n"); ^ user.cpp:31:17: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(ch); ^ /tmp/ccRC3grH.o: In function `main': user.cpp:(.text.startup+0xa5): warning: the `gets' function is dangerous and should not be used.