/in/foo.cc: In function 'int main()':
/in/foo.cc:42:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while(target!=pq.size()){/*if(!appr[pq.top()])printf("%d\n",pq.top());appr[pq.top()]=0;*/pq.pop();}
         ~~~~~~^~~~~~~~~~~