Compilare: user.cpp: In function ‘void DFS(int, int, int)’: user.cpp:22:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int it = 0;it < G[Node].size();it++) ^ user.cpp: In function ‘int main()’: user.cpp:76:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0;i < Sol.size();i++) ^ user.cpp:80:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0;j < Sol[i].size();j++) ^ user.cpp:59:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biconex.in","r",stdin); ^ user.cpp:60:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biconex.out","w",stdout); ^ user.cpp:62:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&N,&M); ^ user.cpp:67:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n",&A,&B); ^