Compilare: user.cpp: In function ‘int main()’: user.cpp:73:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<G[w].size();i++) v[++y]=G[w][i]; ^ user.cpp:62:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("atac2.in","r",stdin); ^ user.cpp:63:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("atac2.out","w",stdout); ^ user.cpp:64:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i%i%i",&n,&m,&u,&w); ^ user.cpp:65:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (i=1;i<=u;i++) scanf("%i",&c[i]); ^ user.cpp:68:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i",&x,&y); ^