Compilare: user.cpp: In function ‘void DFSprecalc(int)’: user.cpp:34:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[x].size();++i) { ^ user.cpp: In function ‘void DFS(int)’: user.cpp:52:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[x].size();++i) ^ user.cpp: In function ‘int main()’: user.cpp:62:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d",&n,&c); ^ user.cpp:63:48: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=1;i<=n;i++) fscanf(fin, "%lld",&s[i]); ^ user.cpp:64:48: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=1;i<=n;i++) fscanf(fin, "%lld",&p[i]); ^ user.cpp:67:35: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d",&x,&y); ^