Compilare: user.cpp: In function ‘void doit(int, int)’: user.cpp:7:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] #define FOR(i,s,d) for(i=(s);i<(d);++i) ^ user.cpp:26:2: note: in expansion of macro ‘FOR’ FOR(j,0,G[i].sz) doit(G[i][j],lev+1); ^ user.cpp: In function ‘int main()’: user.cpp:45:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arb.in","r",stdin); ^ user.cpp:46:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arb.out","w",stdout); ^ user.cpp:48:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:49:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] FOR(i,0,n) scanf("%d",&H[i]); ^ user.cpp:50:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] FOR(i,1,n) scanf("%d",&j),G[j-1].pb(i); ^ user.cpp:52:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&m); ^ user.cpp:53:73: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] FOR(i,0,m) scanf("%d %d",&A[i],&B[i]),A[i]--,X[i+n]=mp(B[i]+lv[A[i]],i); ^