Compilare: user.cpp: In function ‘int dijkstra(int, int)’: user.cpp:64:12: warning: unused variable ‘d’ [-Wunused-variable] ll d = pq.top().d; ^ user.cpp: In function ‘int main()’: user.cpp:125:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i + 1 < path1.size(); i++) { ~~~~~~^~~~~~~~~~~~~~ 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); ^