Compilare: main.cpp: In function 'll bfs()': main.cpp:32:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<a[x].size();i++) ~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:59:15: warning: suggest parentheses around assignment used as truth value [-Wparentheses] while(nw=bfs()) ^ main.cpp:48:33: 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); ^ main.cpp:49:35: 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); ^