Compilare: user.cpp: In function ‘bool bfs()’: user.cpp:41:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0;i < G[a].size();i++) ^ user.cpp: In function ‘int max_flow()’: user.cpp:63:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0;i < G[last].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:93:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("harta.in","r",stdin); ^ user.cpp:94:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("harta.out","w",stdout); ^ user.cpp:96:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:102:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&a,&b); ^