Compilare: main.cpp: In function 'void dijkstra()': main.cpp:29:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[x][y].size();i++) ~^~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:44:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dragoni.in","r",stdin); ^ main.cpp:45:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dragoni.out","w",stdout); ^