Compilare: main.cpp: In function 'int main()': main.cpp:50:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<G[u].size();++i){ ~^~~~~~~~~~~~ main.cpp:20:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dijkstra2.in","r",stdin); ^ main.cpp:21:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dijkstra2.out","w",stdout); ^ main.cpp:24:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&n,&m,&src); ^ main.cpp:26:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&u,&v,&c); ^