Compilare: user.cpp: In function ‘int main()’: user.cpp:77:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("logic.in","r", stdin); ^ user.cpp:78:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("logic.out", "w",stdout); ^ user.cpp:82:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &n); ^ user.cpp:86:17: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s1); ^ user.cpp:87:17: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s2); ^ /tmp/cc4zEUhR.o: In function `main': user.cpp:(.text.startup+0x85): warning: the `gets' function is dangerous and should not be used.