Compilare: user.cpp: In function ‘void dijkstra(int, int)’: user.cpp:56:12: warning: unused variable ‘d’ [-Wunused-variable] ll d = -pq.top().first; ^ user.cpp: In function ‘char nextch()’: user.cpp:15:34: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, 1, MAXBUF, fi); ^ user.cpp: In function ‘int main()’: user.cpp:74:27: warning: ‘id’ may be used uninitialized in this function [-Wmaybe-uninitialized] nod = from[id][nod]; ~~~~~~~~~~~~^ user.cpp:128:13: note: ‘id’ was declared here int id; ^~