/in/foo.cc: In function 'void delet(int)':
/in/foo.cc:49:10: warning: unused variable 'k' [-Wunused-variable]
  int i,j,k,s,v;
          ^
/in/foo.cc: In function 'long long int Kruskal()':
/in/foo.cc:131:8: warning: unused variable 'j' [-Wunused-variable]
  int i,j,u,v,fu,fv,cnt;
        ^
/in/foo.cc:131:10: warning: unused variable 'u' [-Wunused-variable]
  int i,j,u,v,fu,fv,cnt;
          ^
/in/foo.cc:131:12: warning: unused variable 'v' [-Wunused-variable]
  int i,j,u,v,fu,fv,cnt;
            ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:150:10: warning: unused variable 'k' [-Wunused-variable]
  int i,j,k,x,y,z;
          ^
/in/foo.cc:150:14: warning: unused variable 'y' [-Wunused-variable]
  int i,j,k,x,y,z;
              ^
/in/foo.cc:150:16: warning: unused variable 'z' [-Wunused-variable]
  int i,j,k,x,y,z;
                ^
/in/foo.cc: In function 'long long int Kruskal()':
/in/foo.cc:142:9: warning: 'cnt' may be used uninitialized in this function [-Wmaybe-uninitialized]
    cnt++;  s+=g[i].w;//printf("s=%lld\n",s);
         ^