Compilare: user.cpp: In function ‘int main()’: user.cpp:77:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<Hash.C[act].size();j++){ ^ user.cpp:55:35: 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:56:37: 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:58:51: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld %ld %ld\n%s\n",&n,&m,&l,&k,s+1); k++; ^ user.cpp:73:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s\n",a+1); ^