HDOJ1074

import java.util.*;
/** * @author xiliang.zxl * @date 2015-05-08 14:04 */
public class Main {
    /** number: oj1074 title : homework solution task: give a solution to minimize the cost of delay input: 2 3 Computer 3 3 English 20 1 Math 3 2 3 Computer 3 3 English 6 3 Math 6 3 output: 2 Computer Math English 3 Computer English Math solution time complex: 2^n solution brief introduction: use the math bit property : 1 -> 2^15 can imitate all middle station . whats more, this is can be a dp process. design a data structure and use dp theory. abstract model: N task , 2^N middle state , final state is all N task touched. description : all match upper model questions can use this solution template. */

    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        int cnt=scanner.nextInt();
        while (cnt-->0){
            List<Course> list=new ArrayList<Course>();
            int courseCnt=scanner.nextInt();
            while (courseCnt-->0){
                Course course=new Course();
                course.name=scanner.next();
                course.deadline=scanner.nextInt();
                course.needDays=scanner.nextInt();
                list.add(course);
            }
            findSolution(list);
        }
    }
    public static int[]parentAux=new int[32768];

    public static int[]timeAux=new int[32768];

    public static int[]delayAux=new int[32768];

    public static void initAux(int size){
        for(int i=0;i<=size;++i){
            parentAux[i]=timeAux[i]=-1;
        }
    }
    public static void findSolution(List<Course> courses){
        initAux(courses.size());

        int i=0,max= (int) Math.pow(2,courses.size())-1;
        while(++i<=32768){
            if(i>max) break;
            Struct<Integer> struct=invokeDP(i,courses);
            parentAux[i]=struct.parent;
            timeAux[i]=struct.time;
            delayAux[i]=struct.delay;
        }
        List<Integer> orderList=getHomeWorkOrder(max);
        System.out.println(delayAux[max]);
        for(Integer workIndex:orderList){
            System.out.println(courses.get(workIndex).name);
        }
    }

    public static List<Integer> getHomeWorkOrder(int max){
        List<Integer> orderList=new ArrayList<Integer>();
        while(max!=-1){
            int positon=max;
            if(parentAux[max]!=-1)
                positon=max-parentAux[max];
            orderList.add(0,parsePosition(positon,0));
            max=parentAux[max];
        }
        return orderList;
    }

    public static int parsePosition(int position,int offset){
        for(int i=offset;i<=15;++i){
            if(((1<<i)&position)!=0)
                return i;
        }
        return -1;
    }

    public static Struct invokeDP(int i, List<Course> courses){
        //      
        Struct struct=new Struct(0,0,-1);
        if((i&(i-1))==0){
            struct.time=courses.get(parsePosition(i,0)).needDays;
            int delay=courses.get(parsePosition(i,0)).needDays-courses.get(parsePosition(i,0)).deadline;
            if(delay>0){
                struct.delay=delay;
            }
            return struct;
        }
        int position=parsePosition(i,0),bestPosition=position,minDelay=Integer.MAX_VALUE;
        while (position!=-1){
            int time=timeAux[i-(1<<position)],cost=delayAux[i-(1<<position)];
            int delay=courses.get(position).needDays+time-courses.get(position).deadline;
            if(delay>0){
                cost+=delay;
            }
            if(cost<minDelay || (cost==minDelay &&
                    courses.get(position).name.compareTo(courses.get(bestPosition).name)>0)){
                bestPosition=position;
                minDelay=cost;
            }
            position=parsePosition(i,position+1);
        }

        struct.time=timeAux[i-(1<<bestPosition)]+courses.get(bestPosition).needDays;
        struct.parent=i-(1<<bestPosition);
        struct.delay=minDelay;
        return struct;
    }
    public static class Course{
        String name;
        int deadline;
        int needDays;
    }

    public static class Struct<T>{
        T time;
        T delay;
        T parent;

        public Struct(T time, T delay, T parent) {
            this.time = time;
            this.delay = delay;
            this.parent = parent;
        }
    }

}