Compilare: main.cpp: In function 'void dijkstra(int)': main.cpp:21:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<g[a].size();i++) { ~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:39:32: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d" ,&n ,&m); ^ main.cpp:41:42: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d%d" ,&a ,&b ,&c); ^