Compilare: user.cpp: In function ‘int main()’: user.cpp:51:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i < verif.size(); i++) ^ user.cpp:53:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<lista[verif[i]].size();j++) ^ user.cpp:32:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("alpin.in","r",stdin); ^ user.cpp:34:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:39:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i][j]); ^