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){        //注意字母排序        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;        }    }}