Compilare: user.cpp: In function ‘void solve()’: user.cpp:51:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[ok].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:86:27: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&n,&m); ^ user.cpp:91:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%s",a[i]+1); ^