Compilare: user.cpp: In function ‘void dijkstra(int, int)’: user.cpp:35:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<cost[x0].size();i++) ^ user.cpp:61:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<cost[u].size();i++) ^ user.cpp:33:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^ user.cpp: In function ‘int main()’: user.cpp:79:15: warning: unused variable ‘j’ [-Wunused-variable] int m,n,i,j,x,y,x0; ^