Compilare: user.cpp: In function ‘bool bfs(int)’: user.cpp:23:34: 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:52:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[n].size(); i++){ ^ user.cpp:37:36: 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:38:38: 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:40:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:42:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &val); ^