//sort vertices by degrees

//input line format: vid \t num nb1 nb2 ...
//output line format: order vid \t degree

//we do not hold vertex info, like adjacency list, since it will cause load balance issue due to range-based partitioning
//then use a program to extract top-k, and report the degree threshold (and adjusted k if ties are observed)

#include "utils/TeraSort.h"
#include "utils/type.h"

double sampRate=0.001;

class DegreeSort:public TeraWorker<intpair>
{
	char tmp[100];

	public:
		DegreeSort():TeraWorker<intpair>(sampRate, true){}

		virtual TeraItem<intpair>* toVertex(char* line)
		{
			TeraItem<intpair>* v=new TeraItem<intpair>;
			char * pch;
			pch=strtok(line, "\t");
			int id=atoi(pch);
			v->key.v2=id;
			pch=strtok(NULL, " ");
			int deg=atoi(pch);
			v->key.v1=-deg;//use negative degree to put large degree vertices to the head
			return v;
		}

	    virtual void toline(TeraItem<intpair>* v)
	    {
	    	sprintf(tmp, "%d\t%d\n", v->key.v2, -v->key.v1);
	    	write(tmp);
	    }
};

int main(int argc, char* argv[]){
	WorkerParams param;
	param.input_path="/toy_ug";
	param.output_path="/sort";
	param.force_write=true;
	param.native_dispatcher=false;
	DegreeSort worker;
	worker.run(param);
	return 0;
}