Compilare: user.cpp: In function ‘void apply_dijkstra()’: user.cpp:21:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<graf[tata].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:39:39: 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); ^ user.cpp:40:41: 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); ^ user.cpp:42:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n, &m); ^ user.cpp:45:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&x, &y, &c); ^