Compilare: user.cpp: In function ‘int BFS()’: user.cpp:22:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[nod].size(); ++i){ ~~^~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:46:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[n].size(); ++i){ ~~^~~~~~~~~~~~~ user.cpp:34:36: 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:35:38: 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:36:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:38:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&C); ^