Compilare: main.cpp: In function 'int main()': main.cpp:125:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<arcs[a].size(); ++i) ~^~~~~~~~~~~~~~~ main.cpp:142:39: warning: format '%d' expects argument of type 'int', but argument 2 has type '__gnu_cxx::__alloc_traits<std::allocator<long int> >::value_type {aka long int}' [-Wformat=] printf("%d ", distances[i]); ^ main.cpp:102:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dijkstra.in", "r", stdin); ^ main.cpp:103:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dijkstra.out", "w", stdout); ^ main.cpp:107:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ main.cpp:112:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &a, &b, &c); ^