Compilare: main.cpp: In function 'void dijkstra(int)': main.cpp:21:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<graph_orientat[start_node].size();i++) ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp:33:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<graph_orientat[current_node].size();i++) ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:45:39: 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:46:41: 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:49:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ main.cpp:53:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &a, &b, &c); ^