prepare (1/3): 
finished

make (2/3): 
g++ -g -Wall -O2 -o main.o -c main.cpp 
In file included from main.cpp:16:0:
binary_heap.h: In member function 'void binary_heap::percolate_down(int)':
binary_heap.h:169:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while(j<data.size()){
        ~^~~~~~~~~~~~
binary_heap.h:171:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if((j+1)<data.size()){
      ~~~~~^~~~~~~~~~~~
main.cpp: In function 'int main()':
main.cpp:83:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if(q2.size()==node_num){
     ~~~~~~~~~^~~~~~~~~~
g++ -g -Wall -O2 -o main main.o
finished

clean (3/3): 
finished

all task finished, build successfully