Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:20:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<A[nod].size();++i) ^ user.cpp: In function ‘void dfst(int)’: user.cpp:35:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<B[nod].size();++i) ^ user.cpp: In function ‘int main()’: user.cpp:83:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<mat[x].size();++j) printf("%d ",mat[x][j]); ^ user.cpp:50:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("retele.in","r",stdin); ^ user.cpp:51:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("retele.out","w",stdout); ^ user.cpp:52:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.cpp:55:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^