Compilare: user.cpp: In function ‘int bf(int, int)’: user.cpp:43:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<l[x].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:83:37: 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:84:39: 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:85:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N,&M); ^ user.cpp:88:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&capac); ^