Compilare: user.cpp: In function ‘int main()’: user.cpp:66:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int p=0;p<Hash[curr].size();p++) ^ user.cpp:29:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("radio2.in","r",stdin); ^ user.cpp:30:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("radio2.out","w",stdout); ^ user.cpp:31:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d\n",&n,&m,&l,&k); ^ user.cpp:32:14: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(a+1); ^ user.cpp:56:18: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(b+1); ^ /tmp/cc8RUhV2.o: In function `main': user.cpp:(.text.startup+0x82): warning: the `gets' function is dangerous and should not be used.