Compilare: user.cpp: In function ‘int main()’: user.cpp:7:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("par.in", "r", stdin); ^ user.cpp:8:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("par.out", "w", stdout); ^ user.cpp:14:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ",&n); ^ user.cpp:20:18: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(str); ^ /tmp/cc9E0dgi.o: In function `main': user.cpp:(.text.startup+0x73): warning: the `gets' function is dangerous and should not be used.