Compilare: user.cpp: In function ‘bool bfs()’: user.cpp:20:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<G[crt].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:54:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<lst.size(); i++) ^ user.cpp:42:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxflow.in","r",stdin); ^ user.cpp:43:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxflow.out","w",stdout); ^ user.cpp:44:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.cpp:47:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&x,&y,&cost); ^