/in/foo.cc: In function 'bool bfs()':
/in/foo.cc:21:39: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
  for(R int i=1;i<=t;++i) vis[i]=dis[i]=0;
                                 ~~~~~~^~
/in/foo.cc:22:25: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
  q.push(s),vis[s]=dis[s]=1;
                   ~~~~~~^~
/in/foo.cc: In function 'int dy()':
/in/foo.cc:77:19: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long long int' [-Wformat=]
  printf("%d\n",sum);
                   ^