Compilare: user.cpp: In function ‘bool bfs(int, int)’: user.cpp:21:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i< v[x].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:39:39: 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:40:41: 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:41:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf( "%d%d" , &n , &m); ^ user.cpp:44:43: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d" ,&x ,&y ,&capacity); ^