/in/foo.cc: In function 'void dfs(int, int)':
/in/foo.cc:27:4: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
  if(dis[x]>i)
    ^
/in/foo.cc: In function 'int Exdis(int, int, int, int)':
/in/foo.cc:97:6: warning: unused variable 'bj2' [-Wunused-variable]
  int bj2=(z==2);
      ^~~