Compilare: user.cpp: In function ‘int main()’: user.cpp:19:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("parpal.in","r",stdin); ^ user.cpp:20:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("parpal.out","w",stdout); ^ user.cpp:22:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld\n",&t); ^ user.cpp:25:18: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s+1); beg = 1; n=0; fC = 0; ^ /tmp/ccqJVk6W.o: In function `main': user.cpp:(.text.startup+0x93): warning: the `gets' function is dangerous and should not be used.