Compilare: user.cpp: In function ‘void prim()’: user.cpp:36:9: warning: unused variable ‘w’ [-Wunused-variable] int w,u; ^ user.cpp: In function ‘int main()’: user.cpp:70:9: warning: unused variable ‘x’ [-Wunused-variable] int x,y,c; ^ user.cpp:70:11: warning: unused variable ‘y’ [-Wunused-variable] int x,y,c; ^ user.cpp:70:13: warning: unused variable ‘c’ [-Wunused-variable] int x,y,c; ^ user.cpp: In function ‘void prim()’: user.cpp:57:33: warning: ‘u’ may be used uninitialized in this function [-Wmaybe-uninitialized] cost[j]=dist(u,j); ^